| Cover | Profile | Mathematics | Noology | Eusophy | Remarks | Japanese | Mika's World |
I lifted up mine eyes unto the hills, from whence truth hath come.
The present article is an abridged, reorganized, and partly improved translation of its Japanese counterpart, and it amplifies the non-mathematical part of my paper ''Foundations of Eusophy: A mathematical concept of God for the reconciliation of religion and science,'' hereafter referred to as FE. It, in turn, was born of my earlier monograph ''Mathematical Noology: Intellectual machines, logic, tongues, and algebra,'' hereafter referred to as MN. Each part of this article continues to grow as my thinking deepens and my ability to express it in English improves.
Anyone should know the non-mathematical part of FE, or at least the spirit of the new intellectual undertaking proposed and called eusophy there, because it is crucial both for humankind and for individuals. Namely, it leads to an answer to the question
| (1) | What should anyone do? |
and it aims at
| (2) | The pursuit of a way for humankind to survive |
in view of the following alarm based on climate science:
| (3) | The global temperature rise may become a threat to survival of humankind in the not too distant future, if our action against it is not enough. |
Thus, I have decided to write this article in order to introduce eusophy to worldwide general readership.
It is worth noting here that language reflects the mind, but the mind is also shaped by language. When the words we use are misleading, our thoughts and actions may be misled as well. For instance, the widespread term ''global warming'' may unconsciously evoke the idea of a pleasantly mild climate, leading some to underestimate the severity of the crisis and to neglect necessary action. Hence my choice to write ''global temperature rise'' above.
Eusophy is primarily the pursuit of human omniscience in service of the survival of humankind. It also encompasses a wide range of intellectual undertakings — from theoretical reflection to practical action — for survival depends not only on the transformation of the world, but also on our understanding of it and our engagement with it. Since such transformation may be either short-term or long-term, the corresponding intellectual undertakings must likewise span both temporal scales. Even MN and FE are embraced within the scope of eusophy. They deepen our understanding of ourselves, the universe, and God. This understanding is to provide part of the foundations for theoretical reflection. The remaining part of the foundations is to be provided by our understanding of life, death, happiness, and other fundamental aspects of humanity. Eusophy also transcends various boundaries, both visible and invisible, such as national borders, because Alarm (3) is supplemented as follows:
| (4) | The threat posed by the global temperature rise recognizes no boundaries, not even national ones. |
Both ''survival'' in Alarm (3) and ''survive'' in Aim (2) imply ''continuation as a species.'' Therefore, the following taxonomical knowledge is the starting point of eusophy:
| (5) | Humankind is but one among many species. |
This insight, which I call ''The Declaration of Humankind's Origin,'' will be emphasized together with evolutionary theory and climate science wherever appropriate, for the following three reasons:
On the other hand, although humankind is but one among many species, it is not just any species. In several respects, it is uniquely distinguished — most notably by its intellect.
| (6) | Humankind is distinguished from other species by its intellect. |
Intellection is the activity of knowing the objective world, and intellect (HI, human intelligence) is the capacity to know that world. Accordingly, the objective world is the totality of intellectual objects. An intellectual object is called an entity if it is meaningful to ask whether it exists. For instance, ''UFOs'' and ''Peter'' (in ''The Tail of Peter Rabbit'') are entities. An intellectual object is called an event if it is meaningful to ask whether it occurs. For instance, ''UFOs are round'' and ''Peter eats a radish'' are events, as well as their parts ''are round,'' ''eats a radish,'' and ''eats.'' Not all but many intellectual objects may be expressed by language. Linguistic expressions referring to entities are called nominals, while those referring to events are called declaratives. Observation of language and introspection show that the intellectual objects are divided into entities and events. Observation of language also shows that each event is either an attribute or an act of an entity (and the attribute or the act itself) or a relation between entities (and the relation itself). For instance, the event ''UFOs are round'' is an attribute of the entity ''UFOs'' and the event ''are round'' is the attribute itself. The event ''Peter eats a radish'' is a relation between the entities ''Peter'' and ''a radish,'' and the event ''eats'' is the relation itself. The event ''Peter eats a radish'' is also an act of the entity ''Peter'' and the event ''eats a radish'' is the act itself, which is also an attribute of the entity ''a radish,'' showing that someone eats ''a radish,'' and the event ''eats'' is also the attribute itself. Therefore, each event A may involve some entities a1, ..., an for some positive integer n, so that A is sometimes denoted by A(a1, ..., an). Here, a1, ..., an may not be all of the entities involved. For instance, if ''Peter eats a radish,'' ''Peter,'' and ''a radish'' are denoted by A, b, and c, respectively, then A may also be denoted by A(b), A(c), A(b,c), and A(c,b).
The following subsections consist of definitions with examples, hypotheses, observations, and their conclusions. Although they may seem simple or self-explanatory, the purpose of this article is to amplify them.
Let A1, ..., An, and B denote events, where n is a nonnegative integer; if n = 0, A1, ..., An do not exist. Then the following six expressions are equivalent by definition:
This definition in particular says that the symbolic expression A1, ..., An ⇒ B in 6 may be read as in 1 through 5, especially as ''A1, ..., An together imply B.'' Because of these definitions, the expressions 1 through 6 are also equivalent to the expressions obtained by arbitrary permutation of A1, ..., An. To understand causality in Hypothesis 1 below means reasoning, that is, the act of finding out the reason why A1, ..., An ⇒ B, that is, why A1, ..., An together imply B, for some tuple (A1, ..., An, B) of events. If n = 0 in the expression A1, ..., An ⇒ B, it is denoted by () ⇒ B, and B is said to be necessary or inevitable or, in religious context, B is said to have been determined by Providence (God's will). For instance, the event ''x is x'' is necessary for an arbitrary entity x. Obviously, if B is necessary, then A1, ..., An ⇒ B for every tuple (A1, ..., An) of events. If B is not necessary, we naturally say that B is unnecessary or evitable or avoidable. If the negation of B is necessary, we say that B is impossible. If B is not impossible, we naturally say that B is possible. If B is neither necessary nor impossible, that is, if B is unnecessary and possible, we say that B is contingent. As will be shown by ''Proposition on Paradoxes,'' no event is both necessary and impossible. Therefore, every event is either unnecessary or possible. In other words, necessary events are possible, and impossible events are unnecessary. Also, the negation of a necessary event is unnecessary. For instance, the event ''x is not x'' is unnecessary for an arbitrary entity x. A law is an event which is supposed to be necessary. Causality is nontrivial, that is, the following holds:
Thus, our universe may be called a cosmos governed by a profound causality, for the word ''cosmos'' derives from ''kósmos,'' meaning ''order.''
Although I do not adhere to any established religion, I sometimes find myself drawn to religious spaces. At a Christmas Eve service in 2012, I encountered a verse from the ''Gospel of John'' that reads as follows:
All things were made by the Word.
This verse astonished me, for reasons I explain below.
Since 1992, I have been studying intellect (HI, human intelligence) as defined in §1. This inquiry was motivated by the question ''What is humanity?'' and guided by Insight (6). Intellect is inseparably linked to language, in the following sense:
| (7) | Intellect evolved because humankind acquired language. |
This evolutionary process may be outlined as follows:
This entire process may be encapsulated in the above phrase: ''All things were made by the Word.'' Therefore, I was astonished, because it seemed to me that John had already known everything I had just described.
The preaching, however, was disappointing. According to it, ''Word'' in the ''Gospel of John'' does not mean language, but means God's words such as ''Let there be light'' for creating the heaven and the earth. With some hope, however, I turned to the World Wide Web, found that the ''Wisdom of Solomon'' has something to do with ''Word,'' and found out the following two verses in it:
As for wisdom, what she is, and how she came up, I will tell you, and will not hide mysteries from you: but will seek her out from the beginning of her nativity, and bring the knowledge of her into light, and will not pass over the truth.
God hath granted me to speak as I would, and to conceive as is meet for the things that are given me: because it is he that leadeth unto wisdom, and directeth the wise.
These verses seemed mostly adequate to a prologue and an epilogue, respectively, of a certain section of MN which amplifies Insight (7). The latter, however, also seemed inadequate to MN, because I had long felt that science was incompatible with God, while noology in MN is the science of intellectual phenomena.
The above inadequacy, however, marked the beginning of a fortunate chain of unexpected insights. It first led me to the following question:
Question 1: What is God?
And since they say that God is the omnipotent ruler of the universe, this prompted me to consider the following further questions:
Question 2: What is the universe?
Question 3: What is the omnipotent rule over the universe?
Moreover, it soon occurred to me that these questions could be addressed elegantly using the logics — general logic and case logic — developed in MN.
As I defined in §1.1 (Basic concepts in logic 1), intellection is the activity of knowing the objective world, and intellect (HI, human intelligence) is the capacity to know that world. Accordingly, the objective world is the totality of intellectual objects. These objects are divided into entities and events. An intellectual object is called an entity if it is meaningful to ask whether it exists. It is called an event if it is meaningful to ask whether it occurs. The objective world is vast. People engage in intellection only within limited ranges of intellectual objects, according to their interests. The objective world, then, consists of such limited ranges. Because of Insight (7), we can observe these ranges through language. Furthermore, as a mathematical scientist, I have been able to construct mathematical models of such ranges, on the basis of that observation (mathematical models will be discussed in §4 (Mathematical science and models)). These models constitute my answer to Question 2: ''What is the universe?'' In terms of these models, the limited ranges are called universes. Thus, the objective world is a multiverse composed of these universes. They were created by us — by our intellect. This perspective stands in stark contrast to religious belief, in which the universe is typically regarded as the creation of a transcendent deity. It also stands in stark contrast to prevailing physical cosmology, in which the universe is understood to have originated with the Big Bang.
Given this, the objective world and the universes should be called the noo-cosmos and noo-worlds, respectively, and an intellectual object in a noo-world should be called a noo-element of the world. Thus, the noo-cosmos is composed of noo-worlds, whose noo-elements are entities and events. In the mathematical science mentioned above, the noo-worlds are defined as sets, whereas the noo-cosmos cannot be defined as a set due to a certain set-theoretical reason (sets will be discussed in §3 (Noological Set Theory)). Therefore, we use the set-theoretical term ''element'' for noo-worlds, but not for the noo-cosmos. The prefix ''noo-'' derives from the Greek ''noós,'' meaning ''mind.''
Observation of language shows that there exist certain operations on the events. Each operation assigns an event to each tuple (A1, ..., An) of events, for a positive integer n called the arity of the operation. If the operation is denoted by F, then the event which F assigns to (A1, ..., An) is denoted by F(A1, ..., An). For each event A, -A denotes the negation of A. The symbol ''−'' stands for the expression ''It is not the case that'' and therefore is prepositive (incidentally, it should be postpositive in the Japanese word order). If A denotes, say, the event ''UFOs are round,'' then -A is the event ''It is not the case that UFOs are round,'' which is equivalent to the event ''UFOs are not round.'' For each pair (A, B) of events, A & B denotes the conjunction of A and B. For instance, if A and B denote the events ''Peter eats a radish'' and ''Peter eats a lettuce,'' respectively, then A & B is the event ''Peter eats a radish and Peter eats a lettuce,'' which is equivalent to the event ''Peter eats a radish and a lettuce.'' The negation operation assigns each event A its negation -A. It is a unary operation and denoted by the symbol ''-,'' hence -(A) = -A. The conjunction operation assigns each pair (A, B) of events their conjunction A & B. It is a binary operation and denoted by the symbol &, hence &(A,B) = A & B. The negation operation and the conjunction operation are basic ones. There exists a variety of operations, because operations can be composed. For instance, composing the negation operation and the conjunction operation, we obtain the operation which assigns each pair (A, B) of events the event -(-A & -B), although it is equivalent to the basic event ''A OR B.''
Let F be an operation on the events of arity n. Then F is called a deduction if A1, ..., An ⇒ F(A1, ..., An), that is, if A1, ..., An together imply F(A1, ..., An), for each tuple (A1, ..., An) of events. For instance, the conjunction operation & is a deduction, while the negation operation ''-'' is not a deduction, because ''x is x'' does not imply -(''x is x''), or more generally, no necessary event A satisfies A ⇒ -A, as will be shown by ''Proposition on Paradoxes'' and the logical laws in §3.1 (Basic Concepts in Logic 3).
Let F be an operation on the events, n be its arity, and C be a collection of events. Then F(C) denotes the collection of all events F(A1, ..., An) for all tuples (A1, ..., An) of events in C. This notation is different from mathematical notation, where F(C) is denoted by F(Cn).
Let C be a collection of events. Then an event B is said to be generated by C if the following holds:
For some nonnegative integer n, there exists a sequence A0, ..., An of events such that An = B, and for each integer k from 0 through n, the event Ak satisfies one of the following two conditions:
- Ak belongs to C (indeed, A0 belongs to C, because it does not satisfy the following condition).
- Ak belongs to Fk({A0, ..., Ak-1}) for some deduction Fk, where {A0, ..., Ak-1} denotes the collection of A0, ..., Ak-1.
Such a sequence is called an explanation of B by C. Obviously, the following holds:
Suppose Ak satisfies condition 2 above and k' is the arity of the deduction Fk in it. Then there exists a tuple (B1, ..., Bk') of events in {A0, ..., Ak-1} such that Ak = Fk(B1, ..., Bk'), which implies B1, ..., Bk' ⇒ Ak, because Fk is a deduction. Since B1, ..., Bk' belong to {A0, ..., Ak-1}, it follows that A0 , ..., Ak-1 ⇒ Ak. By applying these facts inductively, we can prove the following:
Let L be a collection of laws. If L has the following property called omnipotence, then we say that L is omnipotent:
The following two expressions are equivalent for each tuple (A1, ..., An, B) of events:
- B is an effect of the causes A1, ..., An.
- B is generated by the union L∪{A1, ..., An}.
Here, {A1, ..., An} denotes the collection of A1, ..., An. It follow from Proposition on Generation and Causality that condition 2 implies condition 1. Therefore, the omnipotence of L, in fact, means that, for each tuple (A1, ..., An, B) of events, condition 1 implies condition 2. A similar remark applies to the following definition of omniscience.
If L has the following property called omniscience, then we say that L is omniscient:
The following two expressions are equivalent for each tuple (A1, ..., An, B) of events:
- B is an effect of the causes A1, ..., An.
- There exists an explanation of B by L∪{A1, ..., An}.
Then Proposition on Generation and Explanation shows that the following proposition holds:
If a collection of laws has these equivalent properties, we say that it governs causality.
As a mathematician, I was able to analyze the model universes mentioned in §2.1 (Answer to Question 2), that is, the mathematical models of the real universes (noo-worlds). In particular, in the mother treatise FE, I was able to verify that these models are adequate, by defining causality within each model universe so that it possesses the same fundamental properties as the causality of the real universes (adequacy of mathematical models will be discussed in §4 (Mathematical science and models)). Furthermore, on the basis of these fundamental properties, I was able to prove the following proposition:
According to Proposition on Omnipotence and Omniscience and the above definition of the governance of causality, this property of the collection is equivalent to both omnipotence and omniscience. Obviously, if a collection of laws governs causality, then any collection that contains it also governs causality. Therefore, there exists a unique and maximal collection of laws that governs causality. This leads us to the following four definitions, which include the answers to Questions 1 and 3:
Now, let us turn to the real universes (noo-worlds) and adopt Definitions 1 through 4 for them as well. Then, according to the above-mentioned adequacy of the model universes and Proposition on Causality, the God, so defined for each real universe, is understood to exist and to be omnipotent and omniscient as well.
There exist universes in which either space or time does not exist — such as mathematical universes, which are universes of noo-elements that interest mathematicians. For other universes in which both space and time exist, we can define:
There also exist universes in which no humans exist — such as mathematical or physical universes, which are universes of noo-elements that interest physicists. For other universes in which humans do exist, we can define:
In each monotheistic religion, the deity is, among other roles, an object of both reverence and dread. The God defined in Definition 1 may well be an object of dread for anyone, since the laws that govern causality are profound and deeply involved in every aspect of daily life. However, this God is unlikely to be an object of reverence, as we humans seem capable of reverence only toward personified beings perceived as exalted in spirit. This may appear to be a shortcoming of Definition 1 for those who have guided their actions through reverence and dread toward a transcendent, life-bearing deity. Yet this is more than compensated for by a significant advantage of Definition 1: namely, it has given rise to eusophy — a system capable of generating universally respectable and trustworthy norms of action, grounded in the supreme good articulated in Conclusion 2. Such norms — and those who establish, disseminate, and practice eusophy for the survival of humankind — are worthy of our respect. Moreover, God is connected with the deities of monotheistic religions through the essence of religion articulated in Observation 4. According to Definition 1, God subsumes all laws, such as logical laws, the law of universal gravitation, and likely the law of organic evolution. The latter is not necessarily benevolent to individuals. Therefore, the Problem of Evil can be avoided. Omnipotence, omniscience, and Definition 4 show that God governs Providence and is capable of explaining it; thus, we may say that God is rational. Definition 4 also shows that Providence determines whether a tuple of events implies another — an idea that resembles a traditional formulation in Christian theology. Above all, God is compatible with science, as will be shown below. This compatibility was crucial for me in arriving at Conclusion 1.
The compatibility of God, as defined in Definition 1, with evolutionism can be demonstrated as follows. Evolutionism asserts that:
| (8) | The law of organic evolution created all species, including humankind. |
As noted above, God probably subsumes the law of organic evolution. Therefore, we may also assert that:
| (9) | God created all species. |
In other words, Assertion (8) may be regarded as a refinement of Assertion (9). Thus, God — or rather, creationism — is compatible with evolutionism. Moreover, intelligent design theory is also compatible with evolutionism, since God is intelligent in the sense of being omniscient, as defined in Definition 3.
More generally, God defined in Definition 1 is compatible with science for the following three reasons:
The God defined in Definition 1 differs significantly from the deity of traditional religion. The religious deity is typically believed to have created both the universe and humankind. In contrast, Proposition on Causality suggests that the universe gives rise to God. Moreover, according to §2.1 (Answer to Question 2), the universes (noo-worlds) were created by our intellect. Thus, God is also brought forth by our intellect.
The prologue of the introductory chapter of MN is the proverb ''Know thyself'' in ancient Greece, because it seems as proposing the question ''What is humanity?'' which motivates noology in MN. The proverb is sometimes supplemented as follows:
Know thyself, and thou shalt know the universe and God.
This seems as predicting ''Noology will lead to an understanding of the universe and God.'' In any case, the prediction has come true in the first draft of the mother treatise FE. Some readers have sent me useful comments on it. Among them are the following two from a physicist and a mathematician:
The former led me to Hypotheses 1 through 4, which together with the latter led me to Conclusion 1. Thus, FE has become complete to be the mother of this article.
A clarification of my view on sets is in order here, prompted by the following statement in §2.1 (Answer to Question 2):
In the mathematical science mentioned above, the noo-worlds are defined as sets, whereas the noo-cosmos cannot be defined as a set due to a certain set-theoretical reason.
The set theory presented here is neither naïve nor axiomatic, but rather noological.
- The Noological Definition of Sets
- A set is defined as a collection of entities within a perceived range. These entities are gathered by our intellect, and the set itself is regarded as an entity.
This definition is noological because of the italicized words ''intellect,'' ''perceived,'' and ''entities,'' — an noo-element is called an entity if it is meaningful to ask whether it exists.
Now, we can proceed as in naïve set theory. However, there exist certain differences. Notably, the following holds:
This is because each set is constructed by our intellect, which cannot include the set itself among the entities it gathers in the act of construction. This is analogous to the fact that a dish cannot include itself among its own ingredients prior to being made.
Entities other than sets are called prime entities. For example, the symbol I is a prime entity, as are all of its sequences such as I, II, III, and so on. We call the sequences I, II, III, ... the natural numbers as the ancient romans probably did, and as usual, denote them respectively by 1, 2, 3, ... in the decimal system. Using them, we can construct the sets of integers, rational numbers, real numbers, and so on, in a well-known way. The numbers are all prime entities. Thus, our set theory is open in that it takes prime entities into consideration.
An entitic condition is said to be unbounded if it does not satisfy condition 2 in Proposition on Entitic Conditions. Namely, an entitic condition C is unbounded if, for each set X, there exists a set which contains X and satisfies C. Proposition on Entitic Conditions, then, shows that there does not exist the set of all entities satisfying C. This has various consequences about mathematics:
Since I mentioned Russel's paradox, some remarks on paradoxes may be in order.
An event A is said to be paradoxical if both A and its negation -A are necessary, that is, if () ⇒ A and () ⇒ -A. In fact, no paradoxical event exists. This is verified by using the following logical laws:
It is a good exercise to derive the following laws from the above ones:
The law 6 was used in the proof of Proposition on Entitic Conditions. The above-mentioned fact may be stated and proved as follows:
I define a paradox as a reasoning which concludes that there exists a paradoxical event, which is incorrect according to Proposition on Paradoxes. Incidentally, the prefix ''para-'' in particular means ''incorrect'' and ''dox'' derives from ''dokein,'' meaning ''to think.''
Example 1. Achilles does not catch up with the tortoise:
Achilles runs a race with a tortoise. The tortoise starts a meters ahead of him. Achilles and the tortoise run at b meters per second and c meters per second, respectively, with b greater than c. Then, the distance between them decreases at a rate of (b – c) meters per second, and becomes zero after a/(b – c) seconds, that is, Achilles catches up with the tortoise at that time. On the other hand, he reaches the tortoise's starting point after a/b seconds, by which time the tortoise has moved ac/b meters ahead. He then reaches that new point after ac/b2 seconds, by which time the tortoise has moved ac2/b2 meters further. He reaches that point after ac2/b3 seconds, when the tortoise is ac3/b3 meters ahead; and so on. Therefore, the tortoise remains ahead of Achilles, always, and he does not catch up with the tortoise.
This reasoning concludes that both the event ''Achilles catches up with the tortoise'' and its negation are necessary; hence, it is paradoxical. According to Proposition on Paradoxes, there must be a mistake here. The total time during which the tortoise remains ahead of Achilles is less than the infinite sum (a/b + ac/b2 + ac2/b3 + ・・・), which is equal to a/(b-c) seconds — the exact time at which Achilles catches up with the tortoise. Therefore, the description following ''On the other hand'' up to ''and so on'' at most means ''The tortoise remains ahead of Achilles, until he catches up with it,'' which is correct. The mistake lies in replacing ''until he catches up with it'' with ''always.''
Example 2. There is a declarative which is both false and not false:
Consider the declarative ''This declarative is false.'' If this declarative is false, then it is not false. If it is not false, then it is false.
Let A denote the event ''This declarative is not false.'' Then this reasoning concludes that -A ⇒ A and A ⇒ -A. Hence it is paradoxical by the laws 7 and 8 above. According to Proposition on Paradoxes, there must be a mistake here. Let B denote ''This declarative.'' Then ''this declarative'' refers to the declarative ''B is false.'' Let C denote it. Then the above reasoning in fact concludes that B is false if and only if C is not false, which is correct. Hence B is not equal to C. Probably, misled by the ambiguity of the word ''this declarative,'' the above reasoning assumed that B was equal to C, hence concluded that B and C were both false and not false.
Example 3. Inexpressible entities are expressible:
Let a denote one of the entities which are inexpressible. Then a is expressible as ''one of the entities which are inexpressible,'' and so a is not one of the entities which are inexpressible. Thus, a is not a.
This reasoning concludes that the event ''a is not a'' is necessary, hence paradoxical, because its negation ''a is a'' is also necessary. According to Proposition on Paradoxes, there must be a mistake here. In fact, after expressing an entity as ''an inexpressible entity,'' it is lying as ''it is an inexpressible entity.'' There is another mistake. Every entity is expressible, even by one letter, as has been shown by the above sentence ''Let a denote one of the entities which are inexpressible.'' Similar remarks apply to the paradoxes obtained by replacing ''express'' by ''explain'' and ''define.''
If x is an entity and A is a set, the expression ''x ∈ A'' means ''x belongs to A.'' Russel's paradox in naïve set theory is as follows:
Let A be the set of all sets X which do not satisfy X ∈ X. Then, if A satisfies A ∈ A, then A does not satisfy A ∈ A by the definition of A. If A does not satisfy A ∈ A, then A satisfies A ∈ A by the definition of A.
Let B denote the event ''A does not satisfy A ∈ A.'' Then Russel concluded above that -B ⇒ B and B ⇒ -B. Hence B is paradoxical by the laws 7 and 8 above. According to Proposition on Paradoxes, there must be a mistake here. As shown above, it was found out by proceeding to noological set theory. It is a pity that the initiators of naïve set theory could not find out it and some of them proceeded to axiomatic set theory.
The purpose of the following two sections is to deepen our understanding of humankind from two perspectives. In this section, we consider intellect (HI, human intelligence) in light of Insights (6) and (7).
Just as we possess internal organs for digestion and circulation, we must also possess a neuro-system for intellection — this I call the noo-system or mechanically call the intellection unit (IU) inspired by CPU (central processing unit) and AI. Considering that this system operates electrochemically, I begin with the following electrochemical hypotheses:
I refer to this relation between noo-elements and perceptors as the perception relation. It may also be understood as a relation between the noo-cosmos and the noo-system.
These hypotheses may be illustrated by analogy with a computer monitor. A monitor consists of countless pixels, each of which may be likened to a perceptor. Consider the cover page of this site: apart from the title and the menu, it displays an image of a landscape against a black background. Each pixel in the image has altered its color in response to a specific point in the landscape — these correspond to actual percepts. In contrast, the pixels in the black background are not currently responding to any input and have undergone no transformation — these correspond to potential percepts.
''What are these electrochemical elements?'' I do not know the answer — nor, I suspect, does anyone. Nevertheless, we can attempt to study intellection by constructing and analyzing a mathematical model of it. This approach is, in spirit, akin to that of Gregor Mendel in the 19th century. Mendel constructed and analyzed a simple mathematical model of heredity. While his model involved certain ''elements,'' ours involves ''electrochemical elements.'' He observed pea plants to build his model; we observe the noo-language defined below to build ours. Perhaps he hoped that someone, someday, would answer the question ''What are the elements?'' Likewise, we may hope that someone will one day answer the question ''What are the electrochemical elements?''
We refer to possible expressions of percepts as noo-words (not to be confused with noo-worlds), and we refer to the totality of noo-words as the noo-language. Accordingly, noo-words are classified into actual and potential ones.
Let A, B, and C respectively denote a noo-element, one of its percepts, and one of its expressions. Then we call B a meaning of C, and A a semantic object of C; conversely we call C a representation of A. These relations are illustrated by the following diagram:
A = a noo-element ↓↓ B = one of the percepts of A ↓↓ C = one of the expressions of B = one of the representations of A ↓↓ B = one of the meanings of C ↓ A = the unique object of B = one of the semantic objects of C
Here, the pair of down arrows from A to B shows that the noo-element A may have percepts distinct from B, and similarly for other pairs of down arrows, while the arrow from B to A shows that A is the unique object of B. Since each percept possesses precisely one object, the number of the meanings of C is equal to that of the semantic objects of C.
In order to proceed further, the following mechanical and evolutionary hypotheses are necessary.
The underlined adverb ''usually'' is necessary, because any human system is subject to error.
These hypotheses may be illustrated by analogy with a computer. Perceptors are likened to data, while fundamental perceptors in Hypothesis 2 are likened to the preloaded data (those present at initialization) and postloaded data (those added through experience). The operations described in Hypotheses 2 and 3 correspond to data-processing functions that act on all data.
In the former half of MN, I developed general logic — a general theory of logic systems and deduction systems — in the hope that some specific logic system and some specific deduction system on it would serve as an adequate mathematical model of the IU. More precisely, the formal language of the logic system serves as a model of the PU. Since the perceptors (possible percepts) constituting the PU are the meanings of the noo-words, the formal language models the totality of meanings of the noo-words. The constants and variables of the formal language model the fundamental perceptors described in Hypothesis 2 on the PU. Each constant corresponds to a possible percept whose object remains stable over time, while each variable corresponds to a possible percept whose object changes moment by moment. The deduction system models the totality of deductive operations of the RU. The logic worlds in the logic system serve as models of the noo-worlds. Certain mappings of the set of constants and variables into a logic world can be extended to certain mappings of the entire formal language into that logic world. These mappings model the perception relation. They are neither surjective nor injective, indicating that a noo-element may have no percept, or may have multiple percepts. I have chosen case logic, developed in the latter half of MN, as the adequate model for HI. Thus, the model in MN is comprehensive, as it captures what I call the noo-trinity: the triplet of the IU, the noo-cosmos, and the perception relation between them. It is also conceptual and macroscopic, since the noo-trinity can currently be observed only through the noo-language, which itself is conceptual and macroscopic. In this respect, noology in MN stands in stark contrast to neuroscience, which focuses on the microscopic study of the nervous system.
The formal language in general logic, developed in MN, is defined as a universal sorted algebra. This definition was inspired by the disambiguated language introduced by Richard Montague in his paper ''Universal Grammar,'' included in ''Formal Philosophy: Selected Papers of Richard Montague'' (Yale University Press). The formal language in case logic, also developed in MN, may be regarded as a logical version of the mental language discussed by Noam Chomsky in linguistic psychology. Furthermore, the algebraic structure of the formal language in case logic — as a universal sorted algebra — is a logical reconstruction of the case grammar proposed by Charles Fillmore.
Although the IU is originally the intellection unit, we may also consider emotion, volition, and memory as functions grounded in its structure.
Let p and q be evential percepts. A causal connection of p with q is defined as a sequence a0, ..., an of evential percepts, where n is a nonnegative integer called the length of the connection, such that an = q and, for each integer k from 0 through n, ak satisfies one of the following two conditions:
Here, {a0, ..., ak-1} denotes the collection of a0, ..., ak-1 and the meaning of fk({a0, ..., ak-1}) is explained in the remark below.If a causal connection of p with q exists, then we say that p is causally connected with q and let D(p,q) denote the minimal length of all such connections. Clearly, D(p,q) = 0 if and only if p = q. The causal graph is then defined as the oriented graph whose nodes are the evential percepts and whose arrows are the causal connections.
Let P, Q, A0, ..., An respectively denote the objects of the evential percepts p, q, a0, ..., an in the above definition of a causal connection. They are events. Since an = q, it follows that An = Q. Suppose ak satisfies condition 2 above. Then, by definition, there exists a tuple (b1, ..., bk') of evential percepts in {a0, ..., ak-1} such that ak = fk(b1, ..., bk'). Since fk is a deductive operation, the objects B1, ..., Bk' of b1, ..., bk' satisfy B1, ..., Bk' ⇒ Ak. Since B1, ..., Bk' belong to {A0, ..., Ak-1}, we conclude that A0, ..., Ak-1 ⇒ Ak. If ak satisfies condition 1 above, then Ak is either equal to P or is a law. By applying these facts inductively, we can show that P ⇒ Ak for each k, and in particular P ⇒ Q. Thus, the causal connection of p with q may be regarded as an internal explanation of why P ⇒ Q holds.
As defined in §1.1 (Basic Concepts in Logic 1), an event is said to be contingent if it is neither necessary nor impossible, that is, if it is unnecessary and possible. Accordingly, an evential percept is said to be contingent if its object is contingent. The above remark shows that if p is a contingent evential percept, then p is not causally connected with some evential percept, and some evential percept is not causally connected with p.
We may define the self as the IU equipped with the value origin percept and the causal graph. This definition is justified by the preceding Hypotheses on Emotion, Volition, and Memory, which show that the self governs intellection, emotion, volition, and memory — that is, the entirety of our spiritual activity. Physical activities are consequences of this spiritual activity, enabled by effectors such as muscles.
Incidentally, the model of the IU constructed in MN is algebraic, since the logic developed in MN is itself algebraic in nature. As demonstrated in MN, algebra underlies not only logic, but also the structures of noo-worlds, noo-language, and mechanisms — particularly those governing HI and AI. Thus, we may say ''Algebra, she rules them all.'' This is the reason why the subtitle of MN is ''Intellectual machines, logic, tongues, and algebra'' and the subtitle of my monograph ''Mathematical Psychology'' — the mother of MN — is ''Thinking Machines, Logic, Languages, and Algebra.''
The definitions, hypotheses, and mathematical models presented above provide a foundation for the theoretical investigation of human activity — both spiritual and physical. Indeed, I have proved an analogue of Kurt Gödel's incompleteness theorem for the general logic developed in MN, while my pupils at Tokyo University have established analogues of Gödel's completeness theorem for the case logic in MN. The general incompleteness theorem offers profound insights into the nature and limits of HI, AI, and even unknown forms of intelligence that may exist on far-distant stars. In contrast, the completeness theorems shed light specifically on the structure and potential of HI.
In the mid-18th century, Carl Linnaeus, the founder of taxonomy, named the human species Homo sapiens — ''wise man.'' The completeness theorems, originating from Gödel's work in the 20th century, provide logical proof that humanity can indeed become truly wise. Long before that, however — perhaps even predating the origins of Judaism — the doctrine of original sin taught that all humankind bears the burden of a primordial transgression: the first humans disobeyed God and ate the fruit of the tree of knowledge. Gödel's incompleteness theorem not only offers a logical demonstration of the inherent limits of human intelligence, but also suggests a possible answer to the question: ''What is original sin?'' It is this: by eating the fruit of knowledge, humanity acquired a partial and incomplete wisdom. That, I propose, is the true nature of original sin. And interpreted in this way, the ancient doctrine speaks with renewed relevance in the twenty-first century. For today, humanity possesses the knowledge to exploit the natural world in myriad ways, yet lacks the wisdom to restrain that exploitation. As a result, we now suffer the consequences — punishment, one might say — in the form of global temperature rise and biospherical damage that threaten the very survival of life itself.
The purpose of this section is to deepen our understanding of humankind in light of Declaration (5) and Observation 5.
By definition, a life system is a system whose purpose is its own survival — that is, the continuation of its life — and whose life is the process of autonomous self-reproduction of its components, including itself as a whole. Purposes are inseparably linked to orientations: every purpose necessarily gives rise to an orientation toward itself, and conversely, every orientation presupposes a corresponding purpose. Therefore, a life system can also be defined as a survival-oriented system. Its survival instinct is thus defined as its orientation toward survival.
Terrestrial life systems — animals, plants, bacteria, and so on — are conventionally referred to as organisms. Even viruses qualify as life systems in this framework. However, they can function as life systems only within other life systems, just as naked humans can survive only within the environment of the Earth. Extraterrestrial life systems, as conceived here, may not require organic matter — that is, carbon-based compounds — for their structure or survival.
According to this definition, every life system engages in a struggle for its life through its survival instinct. The survival instinct of bacteria and viruses causes many human diseases and gives rise to many antibiotics, some of which are beneficial to humans. The survival instinct of plants can be observed through time-lapse photography. Notable examples include the following YouTube videos:
Struggle for life is not necessarily competition with other life systems. Rather, it is essentially a strenuous effort in the face of difficulty in continuing life — specifically, in reproducing its components, including itself. As will be shown in §6.5 (Evolution), competition is not the central concept in evolutionary theory, contrary to widespread belief. As suggested by Observation 7 and to be discussed in §6.6, the biosphere is a system sustained not only by competition but also by cooperation.
A life system, being a system, necessarily possesses a clear boundary between its interior and exterior. Since its purpose is the continuation of its life — that is, the persistence of its autonomous self-reproduction process — it must maintain within itself a blueprint and a procedural scheme for self-reproduction. It must also, as needed, acquire materials and sources of energy from its surroundings, store them internally, and discharge surplus substances back into the environment.
These acts of intake, storage, and discharge are all subject, to varying degrees, to the conditions of both the external and internal environments. Consequently, even though the self-reproduction of a life system is autonomous and directed toward its own continuation, it is neither entirely free nor constant. It is constrained to some extent by those conditions, and when the constraints are severe, the process may cease altogether. When the constraints are mild, however, the process can continue, adapting to the conditions as necessary. It should be noted that the external environment of one life system may include the self-reproduction activities of other life systems.
The replicas produced by a life system — whether of itself or of its components — may emerge either within or outside the system. Even if initially produced internally, they may eventually be released into the external environment.
Moreover, these replicas are not necessarily exact copies; they may vary in various ways. Even when they are accurate copies, they may undergo changes after production.
Furthermore, such replicas may either be produced as life systems themselves or may become life systems after their production. In either case, the original life system is called the parent, and the resulting life system is called the offspring. The offspring of the offspring, and so on, are called descendants.
Strictly speaking, an offspring is distinct from its parent, but it may also be regarded as continuous with the parent. If so regarded, each individual life continues until its descendants come to an end. This continuity may be likened to a factory that, even after being rebuilt multiple times, is still considered the same factory as long as the same production process continues. This remark leads to my view of life and death, to be presented in §6.3.
Since self-reproduction is constrained by internal and external conditions, it is more readily achieved in environments where such constraints are minimal. Moreover, as noted above, self-reproduction inevitably involves variation. Depending on the attributes resulting from such variation, the degree of constraint imposed by the environment may change. Thus, as the production of offspring continues — offspring of offspring, and so on — groups of life systems possessing particular attributes may gradually increase or decrease in number depending on their compatibility with internal and external conditions. This principle may be called the principle of gradual change, as it gradually gives rise to various phenomena, including those to be discussed in the succeeding paragraphs.
As stated in §6.1, a life system is a system endowed with a purpose of survival. From this purpose arises the effort for survival — that is, the effort to achieve the purpose of survival. In some life systems, this effort gives rise to intelligence, which serves the attainment of survival. Depending on the degree to which the purpose of survival is fulfilled, emotion may also arise. Furthermore, will emerges as a drive toward achieving survival, and the capacity for memory — that is, for retaining and recalling knowledge acquired through intelligence — also develops. In this way, the mental faculties of intelligence, emotion, will, and memory gradually arise from the structure of the life system oriented toward survival. The culmination of such faculties may be found in the self as defined in §5.
Moreover, the emotions that correspond to the degree of survival fulfillment may give rise to purposes beyond mere survival, and to efforts beyond mere survival efforts. These new purposes and efforts, in turn, give rise to evaluations of whether they are compatible or incompatible with survival. When the living environment is insufficient relative to the number of life systems, some of these efforts — including efforts for survival — may transform into competition among life systems, particularly into competition for survival, that is, competition aimed at achieving the purpose of survival.
As stated in §2.1 (Answer to Question 2), the noo-cosmos is the totality of noo-elements, and intelligence is the capacity to know the noo-cosmos. The noo-elements are divided into entities (things) and events, and each point in time or location in space is regarded as an entity. Therefore, even in life systems other than humans, if they possess sufficient intelligence, a form of self-consciousness may gradually arise — namely, the perception of the boundary of the life system within space-time. This refers to the perception of the surface of a life system at the present moment — the boundary between the internal and external aspects of the life system, at the boundary between past and future. Thus, in this article, we define:
Self-consciousness = Perception of the boundary of the life system in space-time.
However, since the term ''self-consciousness'' is polysemous, we shall refer to this specific sense as self-boundary perception from here onward.
In my monograph ''Mathematical Psychology'' — the mother of MN — I discussed three types of self-consciousness: degree of wakefulness, cognition of one's own thoughts, and sense of self-existence. In this context, cognition corresponds to what this article calls perception, and the sense of self-existence may be understood as arising from the integration of self-boundary perception, wakefulness, cognition of one's own thoughts, and memory.
If we study human self-boundary perception as a form of self-consciousness in mathematical science as discussed in §4 (Mathematical science and models) — though it is beyond our present scope — the object of consciousness may be regarded as certain extremely high-dimensional vector-valued function with time as the independent variable. The elements of the vector represent stimuli to sensory cells at each moment. Consciousness itself may then be defined as the derivative or difference of that function. Thus, the process of consciousness can be understood as a process of differentiation or differencing within the nervous system. This mode of understanding is akin to the microscopic approach of neuroscience, which stands in contrast to the macroscopic approach of MN as explained in §5. Because of this contrast in perspective, neither MN nor ''Mathematical Psychology'' treats self-consciousness as a primary object of study.
People die in many different ways. If we were to regard all forms of death as misfortunes, then — since everyone must eventually die — it would follow that every human being, including the newborn child whose birth is now being celebrated, is destined to end in misfortune. I do not wish to hold such a view of life and death.
Biology suggests a view of life and death that stands apart — not only from the notion that all death is misfortune, but also from religious and ancient views. The reproductive cells produced by your body, when united with those of another, can undergo repeated cell division and become a new human being. While the other cells in your body will eventually age and die, your reproductive cells may live on as a new person who inherits your genetic traits. If no accident or suicide intervenes, this process can continue unbroken from generation to generation. In this sense, every human being is originally endowed with eternal life.
To put it metaphorically, we may think of life as batons. Each individual life is like a baton in a relay race — one without a finish line, without winners or losers. Each of us is entrusted with the vital role of receiving the baton and passing it on, as a member of a team. If one can leave the stage with the peace of mind that one has fulfilled this role, then such a departure can hardly be called unfortunate. Moreover, even after fulfilling this role, one does not usually exit immediately; rather, one often remains to witness the baton being passed on, or even to assist in the passing. This, too, may be seen as a reward for having fulfilled one's role. Or perhaps it is a mistaken sense of completion, and in truth, we are often being urged to pass on many more batons.
These urgings, these rewards, and the very role of passing on the baton of life — all of them are granted to us by the principle of life described in §6.1. It is this principle that allows even the most innocent of girls to grow into a child, then a maiden, fall in love, become a mother, a grandmother, and eventually an ancestor with countless descendants. The same is true for boys. In this way, the baton of life continues to be passed on.
In our modern, scientifically advanced age, I believe that spreading this biologically grounded view of life and death is a sound and compassionate way to help people overcome fear and sorrow in the face of death — both their own and that of others. Moreover, such a view brings with it a beautiful byproduct: a deepening sense of affection and compassion for one's parents and children, and by extension, for one's ancestors and descendants. For your ancestors and descendants are, in a profound sense, your past and future selves. Love for one's descendants naturally leads to the desire to contribute to the survival of humankind — for it is only through the continued existence of humanity that your descendants can live.
This desire lies at the very foundation of eusophy proposed in the mother treatise FE and developed throughout this article, as well as of the answer to Question (1): ''What should anyone do?'' Such a view of life and death may also inspire children to embrace the goal of becoming able to pass on the baton of life. And for children who suffer so deeply — perhaps due to bullying at school — that they feel driven to end their lives, this view may offer a reason to live: to stay alive until they can pass on the baton they have received. For to pass on the baton of life is to meet one's future self in the next generation — a thrilling and hopeful prospect.
Incidentally, in Mozart's opera Die Zauberflöte (The Magic Flute), there is a joyful duet, Pa-Pa-Pa-Papageno, in which a loving couple sings of their future together and the many children they hope to have. Just before this scene, the man had been on the verge of taking his own life. This has led to the popularization of the Papageno effect as a means of suicide prevention in adults. Yet this song may also have a powerful message for children: it tells them that their parents are overjoyed to have become their parents, and it may awaken in them the aspiration to become someone who can pass on the baton of life. In this way, it may help children find happiness and hope.
Answering the question ''What is a species?'' appears to be a difficult task in taxonomy, especially when it comes to classifying extinct organisms known only from fossils. However, eusophy is concerned with the future — specifically, with the survival of humankind as a species. Accordingly, in this article, when I refer to humankind or living beings, I generally mean future humankind or future living beings. Since the present and even the recent past were, not long ago, part of the future, the term ''future'' effectively includes the present and the near past as well.
When it comes to future living beings, the question ''What is a species?'' is not so difficult to answer. I define two individuals as belonging to the same species if they are capable of continuous interbreeding — that is, if they can mate and produce offspring that can, in turn, mate with the original individuals. This is not merely a definition; if it becomes necessary to determine whether two individuals belong to the same species, the determination should be made according to this definition.
Such determination does not require direct mating between the individuals in question or between parents and offspring. It suffices to test mating compatibility with preserved specimens. For this purpose, if feasible, we should freeze and store multiple samples of eggs and sperm from various organisms, updating the specimens periodically.
To illustrate: although humanity comprises many races, the history of intermarriage among them has demonstrated that humans are capable of continuous interbreeding. This confirms Declaration (5): ''Humankind is but one among many species.'' In fact, we must define the scope of humankind itself. I propose that any individual capable of continuous interbreeding with human specimens be defined as belonging to humankind. This definition alone suffices; it is not necessary to determine, for every individual, whether it belongs to humankind.
Horses and donkeys can interbreed, but their offspring are sterile and thus not capable of continuous interbreeding. Therefore, they are distinct species. In contrast, pigs and wild boars are likely the same species, since pigs are domesticated boars. Similarly, dogs and wolves may also be the same species, given their shared ancestry and interbreeding potential.
To divide organisms into species based on continuous interbreeding, the transitivity law must hold: if individual A can continuously interbreed with individual B, and B with individual C, then A must also be able to continuously interbreed with C. This law is both necessary and sufficient for such a classification.
If the transitivity law fails, or if continuous interbreeding cannot be determined in principle, or if the organisms in question do not reproduce through mating at all, then — if classification remains important — it should be carried out using alternative criteria appropriate to the reasons for its importance. The same applies to organisms such as cultivated plants and domesticated animals, which have undergone extensive artificial breeding and for which classification by continuous interbreeding may not be appropriate.
There is little need to be overly concerned about how to classify species, because the only taxonomically important fact in this article is the above-mentioned Declaration (5), and the manner in which species are classified does not affect the explanation of evolution in the next subsection.
In this section, I do not aim to define the standard meanings of the major terms in evolutionary theory, but rather to present my own interpretation. Let us begin by stating what I shall call the principle of evolution — also referred to as the principle of gradual change, as mentioned in §6.2:
Within a single species sharing a common habitat, if individuals possessing a certain genetic trait leave more offspring than those lacking it, then the proportion of individuals with that trait will, over successive generations, approach 100%.
The validity of this principle can be grasped using only elementary arithmetic. Suppose we make a count of the individuals with that trait at fixed intervals. Then we will obtain a series a0, ..., an-1, an, ... of numbers. Here, 0 represents the time of initial count, and 1 in n-1 represents the interval, such as one year, five years, ten years, and so on. Let b0, ..., bn-1, bn, ... be the series of numbers similarly obtained for the individuals lacking that trait. Then the proportion in question is equal to 100an/(an + bn), which is equal to 100/(1 + bn/an). For n = 1, 2, ..., let rn and sn denote the ratios an/an-1 and bn/bn-1, respectively. Then an = rnrn-1・・・r1a0 and bn = snsn-1・・・s1b0, and so bn/an = (sn/rn)(sn-1/rn-1)・・・(s1/r1)(b0/a0). Now, the assumption of the principle of evolution implies that sn < rn, that is, sn/rn < 1 for each n. Here, assume more strongly that there exists a number q such that sn/rn < q < 1 for each n. Then bn/an < qn(b0/a0) for each n. As n continues to increase, bn/an converges to 0 because 0 < q < 1, and so 100/(1 + bn/an) converges to 100, as asserted in that principle.
The conclusion of the principle of evolution — that the proportion of individuals possessing a certain genetic trait approaches 100% over successive generations — does not necessarily mean that the proportion will reach 100%. As the proportion of individuals with the trait increases, the habitat may change — for example, through pollution, depletion of food sources, or loss of suitable living space. In such cases, individuals with the trait may no longer leave significantly more offspring than those without it. As a result, the proportion of individuals with the trait may stabilize at, say, 70%, or even begin to decline.
Assume as in the principle of evolution that individuals possessing a certain genetic trait leave more offspring than those lacking it. Then we may say that the trait — or the individuals possessing it — is adapted to the habitat, or that it represents the fittest in that environment. If the habitat is subject to human influence, as in the case of cultivated fields or breeding facilities — or even if not — we may personify the environment and say that the trait or individuals have been selected by the environment. We may also describe the outcome of the principle by saying that the trait or the individuals possessing it tend toward plenitude — that is, toward being fully present throughout the habitat. Thus, the principle may be restated in various ways:
In the Book of Genesis in the Old Testament, there is a well-known story of Noah's Ark. According to the narrative, when evil had spread throughout human society, God regretted having created humankind. He instructed Noah, a righteous man, to build an ark, and then sent a great flood to destroy all humans except Noah and his family. After the flood, God once again spoke the words He had originally addressed to the first humans: ''Be fruitful, and multiply, and replenish the earth.''
Strikingly, this episode can be interpreted as a parable that illustrates the principle of evolution described above. That is, the individuals (Noah and his descendants) who were selected by the environment (represented by God) go on to tend toward plenitude — they are fruitful, they multiply, and they fill the earth. This interpretation is by no means far-fetched. The Book of Genesis expresses the worldview and understanding of life held by ancient peoples, shaped in a time when civilization — understood, as in Observation 6, as the totality of human knowledge — was still in its infancy. If we read such texts as parables and seek their underlying meanings, we may find that they resonate with modern science and can even be harmonized with a scientific worldview and understanding of life.
Let us suppose that, by some principle distinct from the principle of evolution, a single species of life first emerged in the primordial world. On that basis, I propose the following as the law of evolution, and assume it to be valid:
Through variation during autonomous genetic self-reproduction, plenitude, migration, and repeated dispersion and aggregation, various species have emerged, undergone changes in their genetic traits, and either survived (as species) or failed to survive.
Furthermore, I shall refer to the changes in genetic traits of a species — caused by variation during autonomous genetic self-reproduction, plenitude, migration, and repeated dispersion and aggregation — as the evolution of that species or of those traits. In this sense, evolution refers to changes that occur over successive generations, and in most species, such changes are gradual.
The global spread of the novel coronavirus that began in 2020 provides empirical support for the validity of this law of evolution. The virus that causes COVID-19 undergoes various mutations as it replicates within the human body. Through transmission from person to person, it migrates and undergoes repeated dispersion and aggregation. Variants with higher infectivity — those that leave more offspring — are the fittest within the habitat of the human body and tend toward plenitude. In this way, they survive.
As stated in §6.1, viruses are life systems within the human body. That the law of evolution applies to such viruses is one piece of empirical evidence supporting its validity.
The aim of eusophy — to explore the path to the survival of humankind — does not imply that the survival of other species is to be disregarded. Of course, there are species such as Mycobacterium tuberculosis whose survival we may justifiably seek to eliminate. However, the survival of humankind depends on the survival of many other species. The reasons for this are somewhat intricate.
Let us begin by imagining a time before the advent of agriculture, animal husbandry, or aquaculture, when humans obtained food through hunting, gathering, and fishing. In those times, humans survived by consuming various wild organisms, each of which, in turn, had survived by consuming other organisms. In this way, humans lived within a food chain — a chain of eating and being eaten. This food chain is itself long, but it also connects to even longer chains. The remains of organisms consumed and excreted by animals are further consumed and excreted by other animals, or ultimately decomposed by microorganisms into soil components, or transformed into atmospheric CO2 through combustion or slow oxidation. Over long periods, these remains may also become carbon compounds in the earth or sea, eventually returning to the atmosphere as CO2.
Yet even this is not the end. The remains that have become soil components or atmospheric CO2 are absorbed by plants — through their roots or via photosynthesis — and become part of plant bodies. These plants are then consumed by animals, and the cycle continues. This broader network of relationships, which includes but extends beyond the food chain, forms a system in which ''consuming and being consumed'' occurs in a wide sense, and in which matter circulates and returns to its origin. Rather than the commonly used term ''material cycle,'' I shall refer to this as the food cycle.
Even today, when most of our food comes from agriculture, animal husbandry, and aquaculture, the food cycle continues. While hunting and gathering have diminished, fishing has expanded. All living organisms, including humans, continue to survive within the food cycle. In Observation 7, I provisionally defined the food cycle as the composite of the food chain and the carbon cycle, where the latter refers to the circulation of carbon among the atmosphere, the earth’s crust, the oceans, and living organisms through various carbon compounds.
The relationships among organisms that support survival are not limited to the food cycle. Many organisms survive through symbiosis — mutual support among different species. It is now well known that animals live in symbiosis with bacteria in their bodies. Plants also engage in symbiosis — with fungi, with other plants, and with soil organisms through networks of roots and mycelia. When insects or birds feed on nectar or pollen and assist in pollination, this too is a form of symbiosis. Insects that damage plants may be eaten by birds, or seeds consumed by birds may be dispersed and deposited elsewhere, allowing plants to expand their habitat — these are also forms of symbiosis. Even human cultivation of plants and domestication of animals can be seen as symbiosis: those plants and animals survive by being utilized by humans.
Biologists believe that organelles such as mitochondria and chloroplasts, which support the survival of many organisms, originated from bacteria that once lived symbiotically within primitive cells. These are examples of interspecies symbiosis, but intraspecies symbiosis also exists. Social insects such as ants and bees, and other social organisms that live in structured communities, can be seen as engaging in intraspecies symbiosis. So too can sexually reproducing organisms, in which males and females of the same species coexist and cooperate. In fact, multicellular organisms themselves may be viewed as symbiotic collectives of single-celled organisms of the same kind. Their reproductive cells correspond to the females or queens in social species. Or rather, we may imagine that primitive multicellular organisms, in seeking greater efficiency in survival, ceased expanding as single bodies and instead evolved into social or sexually reproducing organisms. The size and structural complexity of such organisms may have evolved to the extent that maximizes survival efficiency.
The relationships among organisms that support survival are not limited to the food cycle and symbiosis. In many cases, the components of an organism’s habitat are created or provided by other organisms. I shall refer to this relationship as habitat bioprovision. For example, forests, grasslands, seagrass beds, and coral reefs — key components of many animals’ habitats — are created by plants or other animals. The soil that supports plant life is formed from organic remains by insects, fungi, and microorganisms. In parasitism or infection, the body of one organism becomes the habitat of another, often without mutual benefit — unlike symbiosis. What, then, constitutes the habitat of humankind? Even a person living in a high-rise apartment in a concrete jungle depends on food, clothing, and shelter made from materials produced around the world. Their habitat thus includes the habitats of those who produce such materials — farmlands, pastures, fisheries, forests — all of which are shaped and sustained by living organisms. The oxygen that sustains nearly all life today was first produced by cyanobacteria in ancient times and continues to be generated by plants.
From these examples alone, it is clear that the survival of any species depends on the survival of many other species and the sustainability of their habitats, through the food cycle, symbiosis, and habitat bioprovision. The biosphere is the system composed of all biological communities and their habitats. I shall refer to the network of connections described above as the biospherical network:
Biospherical network: the network of food cycles, symbioses, and habitat bioprovisions that link various biological communities and their habitats within the biosphere.
Thus, the biosphere is a system in which biological communities and their habitats are interconnected throughout the biospherical network. The survival of any species depends on the survival of many other species and the sustainability of their habitats, all linked throughout this network. And as stated in Declaration (5), humankind is one among many species and a member of the biosphere, as the title ''Humankind as Part of Biosphere'' of this section suggests. Therefore, I go one step further than the earlier claim that ''the survival of humankind depends on the survival of many other species,'' and assert the following:
The survival of humankind depends on the sustainability of the biosphere.
However, the biosphere has reached its current state through a long process of transformation, and this process will likely continue. What matters is that this transformation proceeds in a direction favorable to humankind — that is, that the biosphere does not evolve into a state that makes human survival more difficult. Ideally, this favorable transformation should continue for as long as possible — perhaps for billions of years, as long as solar energy remains available.
As noted earlier, there may be species such as Mycobacterium tuberculosis whose extinction is acceptable. Therefore, the ''sustainability of the biosphere'' mentioned above does not mean preserving the biosphere in its current form. Rather, it means ensuring that its ongoing transformation continues in a direction that is as favorable as possible to human survival. This is what I meant by the title ''Biosphere for Humankind'' of this subsection.
In the previous section, I referred to the system composed of all biological communities and their habitats as the biosphere. In a similar manner, I shall refer to the system composed of all human communities and their living environments as the humanosphere.
As stated in Declaration (5), humankind is but one among many species. Accordingly, the humanosphere is included within the biosphere. Or rather, since the biosphere is a system in which all life is interconnected through the biospherical network, we may say that the humanosphere is the biosphere itself.
However, within the humanosphere, non-human organisms and their habitats are regarded as components of the human living environment. In this sense, the humanosphere is the biosphere as seen from a human-oriented perspective.
Within the humanosphere, various issues arise that do not arise within the biosphere at large — issues that reflect the distinctive characteristics of humankind. Above all, as stated in Insight (6), humankind is distinguished from other species by its intellect. Accordingly, the various forms of intellectual endeavor become matters of primary concern.
Intellectual exploration may be likened to a downhill ski run. With the right equipment, a high and well-chosen starting point, a right course, and proper techniques, one can reach astonishingly distant and diverse places with astonishing speed — and all the while, with a feeling of pleasure.
Let us set aside, for now, the question of what constitutes the right equipment. As for the high and well-chosen starting point and the right course to take, these are now clear to me: it is to begin from the perspective of seeking the path to the survival of humankind, and to follow a course that leads toward that survival.
Once I stood upon that perspective, I found myself able to see what I had not seen before, to think what I had not been able to think before, and to answer questions I had previously found unanswerable. Each of these insights, each of these questions, proved to be of profound importance. To propose eusophy — a form of intellectual endeavor that takes as its aim the search for the path to human survival — seemed to me not only of the utmost importance, but also entirely natural. It came to me without effort.
The question ''What is the highest good?'' has been asked since the time of the ancient Greek and Roman philosophers, and has continued to be pursued by Western thinkers and religious leaders ever since. I hold deep respect for the early emergence of this question and the long tradition of inquiry it has inspired. That such a question has required centuries of contemplation is a testament to its profound difficulty. And yet, I now find that I can answer it — immediately, and with confidence: That which serves the survival of humankind — this is the highest good.
And yet, I did not arrive at this realization until the year I turned seventy. What a belated awakening. I cannot help but feel astonishment.
But even more astonishing is this: that no one, it seems, has proposed an intellectual endeavor like eusophy before. From antiquity to the present day, there have been countless thinkers of great renown — and yet, none appear to have set forth such a project. Perhaps in earlier times, when the survival of humankind was not yet under threat, it was understandable that no one conceived of such an endeavor. But it has now been decades since the threats to human survival became real. I speak, of course, of global temperature rise.
Several more years passed, and a new realization came to me. It relates to something I wrote in §1 Introduction:
It is worth noting here that language reflects the mind, but the mind is also shaped by language. When the words we use are misleading, our thoughts and actions may be misled as well. For instance, the widespread term ''global warming'' may unconsciously evoke the idea of a pleasantly mild climate, leading some to underestimate the severity of the crisis and to neglect necessary action. Hence my choice to write ''global temperature rise'' above.
Intellectual explorers are those who pursue matters to their very roots. In Japanese, there are many words that express this idea of ''root'' or ''origin'': kon-gen (根元, 根源, 根原), kon-pōn (根本), kigen (起源), kihon (基本), kiso (基礎), and so on. The characters used in these words carry rich metaphorical meanings: 根 (ne, root of grass) and 本 (moto, root of trees) evoke the roots of plants; 源 (minamoto) and 原 (hara) refer to the headwaters of rivers; 基 (motoi) and 礎 (ishizue) signify the foundations of buildings. All three sets of metaphors — roots, springs, and foundations — suggest a beginning (元, 起).
Indeed, in each case, the ''root'' is what comes first: plants begin from their roots, rivers begin from their sources, and buildings begin from their foundations. Thus, we Japanese — and likewise the people of China and Taiwan, who share the heritage of Chinese characters — are naturally inclined, when pursuing the essence of things, to follow this semantic guidance toward the beginning, to trace things back to their origins or to the distant past.
Judging from the English equivalents of these terms — root, origin, source, basis, foundation — it seems that Western thinkers, too, are drawn by similar linguistic cues toward the beginnings of things.
Indeed, those who study the origin of life, the phylogenetic tree of evolution, fossil hominins, or the behavior of modern apes (as close relatives of humans) are all, in one way or another, tracing backward — whether to the earliest forms of life or to the branching points of human evolution. (And I say ''tracing backward and downward'' because phylogenetic trees are often drawn with their roots at the top, inverting the usual orientation of trees.) Likewise, those who study elementary particles are pursuing the roots of matter, and in doing so, they too trace their inquiries back to the beginning of the universe and the distant past.
But this tendency to trace things back to their beginnings or to the distant past has both merits and dangers. Setting aside the merits for now, the danger is clear: it tends to obscure our orientation toward the future. And more critically, because there were no human beings (Homo sapiens) in the distant past, this backward gaze tends to obscure our orientation toward humanity itself.
Indeed, those who study elementary particles have, from the outset, lost sight of the human dimension. And those who study the origin of life, evolutionary trees, fossil hominins, or apes — even if they may have begun with a human-oriented perspective — seem to have lost it, or are in danger of losing it, either by venturing too far into the past or by becoming absorbed in peripheral matters.
The fact that no one has proposed an intellectual endeavor like eusophy may be due, in part, to the tendency among those who pursue things to their ''roots'' to be guided by the semantic pull of such terms — to trace matters back to their beginnings or to the distant past, and in doing so, to lose sight of both the human and the future. They have long neglected the survival of humankind and the question, ''What should anyone do?'' — questions that concern the future of humanity.
Language, while it reflects the mind, also shapes it. And this, too, has both merits and dangers. One of the dangers is that the mind can be misled by inappropriate terms — whether one’s own or those of others.
To be fair, mathematicians are also among those who pursue things to their roots. Before I turned to mathematical psychology, I too was, like most of them, traditionally — or rather, conventionally — focused on numbers, figures, and functions, and from the outset had lost sight of both the human and the future.
In Japan, China, and Taiwan in particular, many people have likely been misled by the term sūgaku (数学), a translation of ''mathematics'' that originated, perhaps, in the Tetsugaku Jii (Philosophical Lexicon, 1881), and which literally means ''the study of numbers.'' This etymology, though historically significant, is no longer appropriate for the present age.
However, in mathematical psychology, as well as in MN and FE, I began with a human-oriented question — ''What is humanity?'' — and pursued not the roots of things, but their core. From there, I sought to extract their essence. In doing so, I was guided not by the metaphors of ''root'' or ''origin,'' but by those of ''core'' (核), ''heart'' (心), ''substance'' (質), ''nature'' (性), and ''life'' (生) — terms that suggest structure, center, spirit, content, and vitality.
This orientation allowed me to maintain both a human focus and a future focus, without forgetting the foundational insight that humankind is one among many species, without losing sight of the target: the survival of humankind, and with a sustained inquiry into the mind that ultimately led me to propose eusophy.
Therefore, I have come to believe the following:
The true essence of intellectual exploration lies in preserving a human and future orientation, pursuing matters to their core, and extracting from that core their essence.
The term ''extracting,'' as I use it here, refers to the act of discerning what is latent or implicit. It takes many forms and can be found throughout the intellectual endeavors of people across cultures and eras.
For example, from the earliest times, humankind has likely observed the plants and animals in its surroundings, gradually coming to recognize the commonality we now call ''life.'' From this recognition, people began to group all such beings together under the concept of ''living things.'' In doing so, they extracted the idea of life from the diversity of plants and animals, and then extracted the concept of living things from the totality of things. Life came to be seen as the essence of living beings, and the possession of life as their essential nature.
In this context, the pronoun ''what,'' as in ''what has life,'' functions as a marker of extraction. From the perspective of linguistic morphology — the study of the structural rules of language — such pronouns may be called nominalizers, as they turn declaratives (linguistic expressions referring to events) into nominals (linguistic expressions referring to entities). But from the perspective of linguistic semantics — the study of meaning — they may more aptly be called extractors, as they serve to extract certain entities from the totalitiy of entities.
The foundation of modern mathematics lies in the concept of the set, as explained in §3 Noological Set Theory. And the tool for forming sets is precisely this act of extraction. In this way, the semantics of language connects to mathematics through extractors and the concept of sets.
Grammar, too, is a discipline that extracts the structural rules of language as its essence. Its origins can be traced back to ancient Greece. However, from the perspective of mathematical psychology and the ancestor treatise MN, the true essence of language lies not in its morphological rules, but in its semantic ones.
Likewise, ancient Greek philosophers recognized that reasoning — particularly in the form of syllogisms — played a central role in thought, and thus laid the foundations of logic. They extracted these logical laws as the essence of thinking itself. Ancient Greek grammar and logic eventually developed into modern mathematical logic, which now serves as an indispensable tool in AI engineering, in the semantics of language, and — more importantly — in answering the questions posed in mathematical psychology, MN, and the mother treatise FE: What is intelligence? What is the universe? What is God?
In the seventeenth century, Newton explained the motion of the planets around the sun by means of the law of universal gravitation, using mathematics. In doing so, he extracted this law as the essence of planetary motion. In the eighteenth century, Linnaeus began the classification of living organisms, not by tracing each species back to its origin, but by extracting essence and essential nature — other than simply ''life'' or ''being alive'' — from plants and animals, and using these to classify them. In the nineteenth century, Darwin published ''On the Origin of Species,'' but he did not trace each species back to its root. Rather, he pursued the phenomenon of the rise and fall of species to its core, and from there extracted the law of evolution as its essence.
Indeed, not only Darwin, but all the figures mentioned above — whether explicitly or implicitly — pursued matters not to their origins or roots, but to their core, and from that core extracted their essence or essential nature.
The laws they extracted — such as the law of universal gravitation or the law of evolution — could not have been discovered through direct observation alone, even with the aid of telescopes, microscopes, or X-rays. Newton reasoned that just as an apple falls to the ground due to gravity, so too do the planets fall continuously toward the sun under gravity, and in doing so, orbit it. Darwin’s reasoning is well known and widely taught in schools.
Thus, extraction includes not only observation with the physical eye, but also what we might call observation with the mind’s eye — that is, reasoning. The examples of Newton and Darwin represent paradigmatic cases of such extraction.
There is a reason why mathematics appears so frequently in these explanations. Mathematics, in its original and proper sense, is not merely the study of numbers, shapes, or functions. Rather, it is a tool of mathematical science as discussed in §4 (Mathematical science and models) — a means of understanding phenomena by extracting mathematical concepts that express the core essence or essential nature of things, through observation and reasoning, and then analyzing them mathematically. Here, ''mathematical'' no longer means ''pertaining to numbers, shapes, or functions,'' but rather ''logical on the foundation of set-theoretic concepts.''
Earlier in this section, I wrote: ''Let us set aside, for now, the question of what constitutes the right equipment.'' Mathematics in the above sense, alongside empirical observation and experimentation in science, is surely one of the right pieces of equipment. Without acquiring and using mathematics, our intellectual endeavors risk being constrained — our hands and feet bound, our paths narrowed, misdirected, or needlessly prolonged. This is symbolized by the fact that even questions such as ''What is intelligence?'' ''What is the universe?'' ''What is God?'' can be answered with precision through mathematical science, as suggested in §2 and §5.
Philosophers, theologians, and scholars of religion ought to be those who can answer such questions with clarity. And yet, perhaps because they have distanced themselves from mathematics, they have largely failed to do so. Indeed, philosophers have long debated the existence of God — between theism, atheism, and agnosticism. While the seriousness of the question is undeniable, the fact that this debate has continued for over a thousand years suggests that it has been, in many ways, unproductive. Gödel, whose work I discussed in §5 in relation to the incompleteness theorem, the completeness theorem, and original sin, even attempted a logical proof of the existence of God. But this, too, has become the subject of further philosophical controversy.
To be fair, mathematicians — myself included, before I turned to mathematical psychology — have largely remained bound by convention, focusing narrowly on numbers, shapes, and functions, and perhaps losing sight of the fact that mathematics was originally meant to serve as a tool for mathematical science.
There are many such unproductive paths. To avoid them — and to find our way out of them — I invite you to read on, and to learn about eusophy.
Earlier, I wrote: ''this tendency to trace things back to their beginnings or to the distant past has both merits and dangers. Setting aside the merits for now...'' But in truth, the merits and significance of tracing things back to their origins or to the distant past must also be evaluated in terms of whether they serve a human-oriented and future-oriented perspective — that is, whether they contribute to the betterment of humanity’s future.
A striking example of such merit and significance is the alarm that climate scientists have been sounding — what I referred to earlier as Alarm (3). This alarm can be elaborated as follows:
Alarm: Since the Industrial Revolution, which began in Britain in the latter half of the 18th century, humans have been burning fossil resources on a massive scale, releasing vast amounts of carbon dioxide (CO2) into the atmosphere. As a result, the atmospheric concentration of CO2 has risen to dangerous levels, leading to global temperature rise. Historically, CO2 has been both emitted into and sequestered by the Earth’s crust, oceans, and living organisms. Despite fluctuations, its atmospheric concentration remained relatively stable over long periods. However, since the Industrial Revolution, the rate of human-induced CO2 emissions has far outpaced the Earth’s natural capacity to reabsorb it, resulting in a net accumulation and consequent global temperature rise. This warming constitutes a grave and immediate form of primary biospherical damage — a disruption of the life-sustaining systems of the planet — and poses a serious threat to the survival of humankind in the near future. Therefore, global temperature rise must be halted by ending the large-scale combustion of fossil resources and achieving net zero carbon dioxide emissions. And at present, it is still possible to do so.
This alarm warrants further explanation.
First, the term fossil resources refers to underground materials derived from ancient life forms, such as coal, petroleum, and natural gas. These resources not only emit gases that cause global temperature rise and atmospheric pollution when used as fuel, but also serve as raw materials for synthetic resins (plastics) and chemical fibers. When incinerated, these materials release gases; when discarded, worn down, or degraded, they release microplastics into the environment. These processes contribute to global temperature rise and to the pollution of the atmosphere, soil, rivers, lakes, and oceans — forms of biospherical damage.
This is why, in this article, I often refer to coal, petroleum, and natural gas not as fossil fuels but as fossil resources. Terms such as carbon offsetting, carbon neutrality, and decarbonization are also commonly used to describe efforts to reduce emissions. However, I find the focus on ''carbon'' in such terms to be misleading. Carbon is not the problem. Unlike carbon dioxide, carbon itself is an essential element — indispensable to all living organisms, including humans, as a fundamental component of organic matter. It is carbon dioxide (CO2), not carbon, that must be identified as the true culprit.
My insistence on precise terminology stems from the fact that, as discussed earlier, the mind is easily misled by inappropriate or suggestive language — whether one’s own or that of others. This concern also connects to the next point.
It is also necessary to explain why global temperature rise constitutes a grave and immediate form of primary biospherical damage. Terms such as ''climate change,'' ''climate crisis,'' ''climate emergency,'' ''climate calamity,'' ''climate catastrophe,'' ''climate dystopia,'' and ''climate apocalypse'' are often used in this context. While words like ''crisis,'' ''emergency,'' and ''catastrophe'' may be appropriate, I believe we should avoid using terms like ''climate'' and ''change.''
The term ''change'' carries the connotation of something that shifts on its own, which may lead people to believe that global temperature rise is a natural phenomenon, unrelated to human activity. This undermines the acceptance of the scientific findings presented by climate researchers.
Likewise, the term ''climate'' tends to direct attention toward atmospheric and terrestrial phenomena — such as temperature, wind, and precipitation — while drawing attention away from the oceans. It also obscures the true nature of the problem, which cannot be neatly categorized under the label of ''climate.''
The real problem: Global temperature rise ultimately leads to the depletion of surface resources — including freshwater, arable land, fisheries, forests, and habitable zones — and to increased health risks, thereby making our daily lives increasingly difficult.
The first issue with focusing solely on ''climate'' is that the oceans have absorbed a significant portion of the excess heat and CO2 from the atmosphere. Thus, global temperature rise has likely affected the oceans — through rising temperatures, acidification, and shifts in marine ecosystems — even before its full effects are felt in the atmosphere or on land. Once the oceans reach their limits of absorption, the heat and CO2 they have stored will be released back into the atmosphere.
The second issue is that abnormal heatwaves in the atmosphere and oceans have already led to the rapid melting of glaciers, icebergs, and ice sheets in mountainous and polar regions. These are direct consequences of global temperature rise. In addition, abnormal cold spells, droughts, torrential rains, and violent storms have become more frequent worldwide. These phenomena can be understood by analogy: just as heating a flask of water causes irregular changes in the temperature, density, and flow of the water and air inside, so too does global temperature rise increase the turbulence and unpredictability of the Earth’s atmospheric and oceanic systems.
As a result, surface resources are being depleted in real and measurable ways: water shortages for daily life and industry, declining agricultural and livestock productivity, collapsing fisheries, forest fires caused by dry air, landslides and floods from heavy rains, and the submergence of inhabited areas due to rising sea levels. According to the World Health Organization, heatstroke and other health hazards — both direct and indirect consequences of global temperature rise — are also on the rise. All of these factors are making daily life more difficult for people around the world.
In this way, global temperature rise and the biospherical changes it causes — both directly and indirectly — constitute a grave and immediate form of biospherical damage. Moreover, because global temperature rise is the primary cause of many other forms of biospherical damage, it can be called a primary biospherical damage.
Global temperature rise poses a serious threat to the survival of humankind in the near future. This is because of the following projection:
Projection: If we continue to burn fossil resources and release large quantities of CO2 into the atmosphere, the atmospheric concentration of CO2 will continue to rise. As a result, the greenhouse effect will intensify, and global temperature rise will accelerate. Eventually, the natural world will begin to release even greater quantities of greenhouse gases that it has long stored — gases such as water vapor, CO2, and methane, which are currently sequestered in the oceans, seabed hydrates, permafrost, and forests. This natural release, combined with ongoing warming, will create a vicious cycle in which warming begets further emissions, and those emissions, in turn, drive further warming. As this cycle repeats, the cumulative effect will be an accelerating rise in global temperature, ultimately rendering the Earth too hot for human habitation.
The term ''accelerating rise'' here refers to a runaway increase — an escalation beyond human control. Such runaway phenomena are not limited to global temperature. They can be either accelerating or non-accelerating, but in this case, the concern is specifically with accelerated runaway warming.
A vivid example of such escalation occurred in 2020, when the global spread of COVID-19 led to a sudden and dramatic spike in infection rates. Graphs depicting the number of infections showed a steep, upward curve — a textbook case of an accelerating runaway phenomenon.
The phrase ''too hot for human habitation'' brings to mind the planet Venus. Venus, often called Earth’s ''sister planet,'' has an atmosphere composed almost entirely of CO2 and an extremely high surface pressure. As a result, its surface temperature reaches approximately 470°C, making it utterly uninhabitable for humans. While there may be other such planets, Venus is particularly evocative: it resembles a vision of Earth after a catastrophic escalation of global temperature rise, a world where the biosphere has vanished in a blaze of heat.
For this reason, I refer to the above projection as the Venusian Scenario. It is one of the Apocalypse Scenarios, but it is an avoidable apocalypse — and therefore worth serious consideration.
In this scenario, the phrase ''greenhouse gases stored in the natural world'' refers to substances such as water vapor, CO2, and methane, which are currently sequestered in the oceans, seabed hydrates, permafrost in the far north, and forests. The phrase ''natural release'' refers to the breakdown of these storage mechanisms due to rising ocean and air temperatures — increased evaporation, thawing of hydrates and permafrost, and more frequent forest fires due to drier air. There may be other mechanisms of natural storage and release, some of which remain unknown.
Among greenhouse gases, methane is particularly concerning. Although it receives less attention than water vapor or CO2, methane is stored in many of the same places. While its atmospheric lifetime is relatively short — on the order of a decade — its greenhouse effect is dozens of times stronger than that of CO2.
Thus, we must be concerned not only with CO2 but also with the atmospheric concentration of methane. According to a graph published by the Japan Meteorological Agency in November 2023, titled ''Trends in Atmospheric Methane Concentration,'' the global average concentration of methane, after a brief plateau in the early 2000s, has been rising acceleratingly since around 2007.
The Venusian Scenario, when broken down through repeated syllogistic reasoning, reveals the underlying causal structure:
At present, many countries around the world have set a goal of achieving net zero CO2 emissions by 2050. This is likely because projections indicate that, without such action, global temperature will continue to rise uncontrollably.
Some critics argue that these projections are unreliable. However, current statistics show that the vast majority of climate scientists consider them to be valid. Even if we were to concede, for the sake of argument, that the probability of these projections being accurate is only 50%, we must weigh the consequences of two possibilities:
In earlier times, when the Venusian Scenario had not yet been proposed, the balance between these two might have been debatable. But now, the situation is different. If the projection is valid and we fail to act, the worst-case outcome is the Venusian transformation of Earth — an irreversible catastrophe. If the projection is invalid and we act regardless, the worst-case outcome is economic loss from halting the large-scale combustion of fossil resources — a loss that is, in principle, reversible. Clearly, the former risk is far more severe.
Now, the surface temperature of Venus is approximately 470°C. This extreme heat is likely capped by certain physical laws. In the case of infectious diseases, such as COVID-19, even if the number of infections rises rapidly, the eventual increase in immunity leads to a peak and subsequent decline. Similarly, during the 2011 Great East Japan Earthquake, the temperatures of the reactor cores at the Fukushima No.1 Nuclear Power Plant rose sharply, but eventually peaked and declined due to cooling efforts. An article titled ''Will Global Warming Run Out of Control?'' published by Japan’s National Institute for Environmental Studies suggests the following:
While the mechanisms of natural greenhouse gas release — especially methane — are not yet fully understood, current research does not conclusively indicate that global temperature will continue to rise without limit.
From this, we may cautiously hope that even if global temperature rises rapidly for a time, it may eventually peak or decline for some reason. Indeed, we must hope so — for without such hope, there is no solace.
And yet, hope alone is not enough. What matters is where the temperature peaks or begins to decline. Even if it levels off at 470°C, like Venus, that would offer no salvation.
History offers grim reminders. During the Black Death in the mid-14th century, the number of infections soared uncontrollably. Before the peak was reached, countless lives were lost. According to a National Geographic Japan article dated May 4, 2020, titled ''The Black Death That Killed One-Third of Europe: A Historical Lesson,'' one-third of Europe’s population perished. Such a peak offers no comfort.
The article quotes a historian who suggests that the plague helped usher in the Renaissance and modern European society. While this may reflect the historian’s diachronic and holistic view of society, it seems to overlook the dignity of each individual life lost in the process.
Moreover, if we take an even broader historical view, we see that the Industrial Revolution — originating in modern European society — led to the large-scale combustion of fossil resources and massive CO2 emissions. This, in turn, has caused global temperature rise, which now threatens the very survival of humankind.
In the case of the Fukushima No.1 Nuclear Power Plant, the reactor cores likely stopped heating only because they had already melted down — a catastrophic outcome. Thus, even that peak was a mixed result, not a true salvation.
As for global temperature, even a few degrees of warming beyond pre-industrial levels is enough to make human life difficult. In August 2024, for example, Japan experienced daily highs near 40°C across many regions. News reports warned of ''life-threatening heat,'' advised people to avoid non-essential outings, and predicted negative impacts on agriculture, as well as increased damage from typhoons and prolonged heavy rains.
Given that Japan’s summer temperatures have already risen several degrees above pre-industrial levels, a few more degrees of warming — even if followed by a plateau — would offer no salvation. There is no time left to waste.
Some reports have described the current heat as a ''disaster-level heatwave.'' But this is not a natural disaster. It is a man-made calamity, a form of pollution caused by the massive combustion of fossil resources and the resulting CO2 emissions. And because this human activity can be halted by transforming society, the disaster can still be prevented.
Yet those at the helm of society do not appear to be taking the need for transformation seriously. One cannot help but ask, in all sincerity: ''What exactly do they intend to do?''
Only when we see the leaders of society take this crisis seriously — only when they show us, clearly and unequivocally, that they are committed to change — will we, the people, feel reassured and inspired to walk alongside them toward a better future. Like the people led by the goddess of liberty in Delacroix’s painting of the French Revolution. What, then, is the goddess of social transformation? Tokyo Electric Power Company (TEPCO) has published a roadmap for the decommissioning of the plant, with completion targeted around 2051. Although the meltdown of three reactor cores was a grave disaster, the mere publication of this roadmap has brought a measure of reassurance.
We now await similar roadmaps from governments and from industries involved in power generation, manufacturing, and transportation — roadmaps toward the goal of net zero CO2 emissions by 2050. The United Kingdom and the state of California in the United States, for example, have announced bans on the sale of gasoline-powered and CO2-emitting vehicles by 2035. These announcements can be seen as parts of such roadmaps.
While we may hope that the ''goddess of social transformation'' will soon descend, the logic of the Venusian Scenario compels us to extend it as follows:
If we continue on our current path, global temperature will rise uncontrollably, and before it ever peaks or declines, the Earth will become too hot for human life.
As discussed above, it is a mistake to consider global temperature, infectious disease case counts, nuclear reactor core temperatures, and CO2 emissions in isolation. These phenomena are not separate events, but rather interconnected outcomes of a continuous chain of human actions.
In the mid-14th century, the Black Death swept across Europe. This pandemic, in turn, contributed to the emergence of the Renaissance and the birth of modern European society. That society gave rise to the Industrial Revolution, which led to the large-scale combustion of fossil resources and the massive release of CO2. This, in turn, caused global temperature rise and the rapid advancement of science and technology. As a result, nuclear fission came to be used for weapons and power generation, leading to fears of nuclear war and the occurrence of catastrophic nuclear accidents.
While pandemics may appear to be natural disasters, they too are, in fact, rooted in human social behavior. Thus, all of these events — pandemics, global temperature rise, nuclear risks — are not isolated incidents, but rather a single, continuous sequence of human-caused phenomena that now threaten the survival of our species.
Therefore, we must go beyond analyzing each issue in isolation. We must quantify not only infection rates, reactor core temperatures, CO2 emissions, and global temperature, but also the risks associated with the use of nuclear technology. Ultimately, we must develop a way to quantify the aggregate risk of human extinction — a measure of the threats to human survival that arise from our own actions.
The Doomsday Clock, maintained by the Bulletin of the Atomic Scientists, may be seen as the first attempt at such quantification. However, it remains largely a subjective measure.
Humanity has not yet developed an objective method for quantifying the threats to its own survival — threats that are, in essence, self-inflicted. And if we consider the continuous chain of events described above, it seems clear that this unknown self-extinction risk is steadily increasing.
This concludes the explanation of the climate scientists’ alarm. What this alarm calls for is reflection on the past, recognition of the present, a sense of crisis about the future, and action grounded in all three. Specifically, it urges us to reflect on the past — that global temperature rise has been caused by humanity’s large-scale combustion of fossil resources and the resulting massive CO2 emissions; to recognize the present — that global temperature rise constitutes a grave, immediate, and primary form of biospherical damage; to feel a sense of crisis about the future — that this warming threatens the survival of humankind in the near term; and to act — to halt the combustion of fossil resources and achieve net zero CO2 emissions.
This alarm traces the origins of global temperature rise back to the time of the Industrial Revolution, using the methods of mathematical science to analyze the past. It also uses those same methods to forecast the near future, and based on those forecasts, it proposes concrete actions to be taken in the present. In doing so, it implicitly issues the following warning:
If we spend all our time looking backward, we may lose the future before we even understand the past.
In this form of climate science, I see a model — an ideal embodiment — of what Intellectual Exploration for the Future ought to be.
(to be continued)