Evolution and Mind

EVOLUTION AND MIND. In current usage the word "evolution" is sometimes restricted in such wise as to render it applicable only to plants and animals, sometimes so extended as to be applicable throughout nature. Closely connected with this difference of use is the place assigned to mind in or in relation to nature. Some of those who advocate the restricted usage urge that evolution is due to the agency of mind; most of those who accept the unrestricted usage interpret mental progress in terms of evolution.

Unrestricted Evolution.

Since the noun here stands for a concept of wide range it needs suitable qualification to indicate its special application. Thus we may discuss cosmic, organic, mental, or social evolution; the evolution of the solar system, of a continent, of scenery; of this or that family of animals or plants; of the atom, the molecule, the crystal. It is clear, there fore, that one must state that which is common to each of these several instances. The noun must have in all cases some compre hensible meaning, though this can only be expressed in compre hensive form. It may take form in a broad generalization. Thus one may say that any set of events or state of affairs, physical or mental, which exemplifies evolution is a passing phase in an orderly sequence and comes into existence under such conditions that its place in the sequence, its relations to precedent and subsequent phases, and its relations to other surrounding events, are inter pretable under the accredited method of scientific procedure.

There is, however, difference of opinion as to the distinctive character of the method of procedure in inductive science. Some say that the accredited method in physics is now a discredited method in biology. Each writer should therefore state what he means. That which is here meant may be best expressed in terms of events and relations, on the understanding that things, such as molecules or crystals, and living organisms, such as animals or plants, are, for science, no more and no less than orderly clusters of events in relation. One finds that clusters of events and sets of events are in quantitatively changing relations to each other—relations temporal, spatial, and physical, and those which, in the broadest sense, we speak of as mental. One finds that with change in these relations the course of events changes. Hence one says : Given such and such modes and changes of relatedness, such and such is the course of events.

It is clear that any course of events implies temporal advance. Selecting, then, some set of events as a field of inquiry, one makes three successive snapshot records of three phases in temporal advance. If all three phases are alike there is no evidence of evolution. But if the phases are different, say 1, m, and n, we have the kind of evidence on which the unrestricted concept of evolution is based—unrestricted because it is applicable to any set of events which is the subject-matter of inquiry. At the phase in the course of events differs in character from that cur rent at the precedent phase 1, and from that current at the sub sequent phase n. That, however, is only what one observes. In a scientific interpretation of what one observes one seeks an answer to the question : What changing relations are in being during the changing course of events ? This subdivides into two : ( I ) What are the intrinsic relations within the given set of events? (2) What are the extrinsic relations to other events? If answers can be given to these questions the observable passage through the phases 1, m, and n is scientifically interpreted.

If the snapshots are taken at wide intervals of time, and if the phases 1, rn and 71 are markedly different, one may be unable to say what relations, intrinsic and extrinsic, are or were in being during the time-span intervening between the snapshots. This is the chief difficulty that attends the interpretation of the irre coverable past. The events themselves and their inner and outer relations have to be filled in under more or less probable con jecture.

Where evolution is in progress in like sets of events with like routine of advance, snapshots can be taken at shorter and shorter time-intervals. One must realize that in practice 1, m and n symbolize recorded observations, and that difference in symbol denotes difference of character. If there be no difference of character, there is no evidence of evolution. One's aim is to get records at such minimum intervals in next-to-next snapshots as may give evidence of evolutionary change. A further question then arises. Is the difference at minimum interval such as to lead us to infer a seemingly sudden jump from next to next? If so, the new character is said to be "emergent" (see EMERGENCE). In some cases there do seem to be critical turning-points—for example, from atom to molecule, or from molecule to crystal unit, or from not-living to living—in the characters of some clusters of events, with new modes of relatedness that swiftly, if not suddenly, appear on the scene of nature.

Evolution and Dissolution.

We now turn to a question of different import. Does every enchained sequence of natural events, in so far as there is observable change, furnish an instance of evolutionary advance? It was one of Herbert Spencer's note worthy contributions to the discussion of changes in sequential order that he sought to distinguish phases of events as in some sense lower and higher. On this distinction there follows that be tween passage from lower to higher, for which he reserved the name "evolution" and the passage from higher to lower, which Spencer spoke of as "dissolution." Since both directions in pas sage occur throughout nature, it is desirable thus to use different words for one and the other, or, at all events, to distinguish be tween positive and negative (or progressive and regressive) evolution. There is, however, difficulty in formulating criteria of higher and lower, especially as applicable to all instances of one or other respectively; for n may be higher or lower than m in complexity, in integral unity, in quality or in value. So long as due provision be made for quality and value, it may be sug gested that complexity in the constitution of any 1, m or n, and unity of the plan or organization may generally serve to distin guish higher from lower in any context under consideration.

In each specific context some distinction between lower and higher is commonly drawn by those who deal with matters which fall within that context. Progressive advance from lower to higher, or regressive degradation or degeneration in the opposite direction, has often to be reckoned with. And in the light of snapshot evidence the question often arises whether some m has come into existence under positive or under negative evolution. Let m, for example, be an atom of lead. There is evidence of its natural origin in isotope form, by regressive evolution (Spencer's dissolution) of the uranium or the thorium atom. But there is, as yet, no direct evidence of its origin by progressive evolution. If, however, m be a molecule, say of water, there may be evidence of its origin in this instance by progressive evolution, in that in stance by the dissolution of some more complex molecule. And if m be an organism, or some phase of its life, or some stage in the development of one of its organs, the present status of m may be on the ascending line of evolutionary progress from lower to higher or the descending line of regressive degeneration.

Biological Evolution.

Under division of labour special de partments or branches of scientific inquiry have been demarcated for the prosecution of intensive work and thought. The biologist chooses as his province the field of living organisms under in trinsic and extrinsic relations. He may accept the hypothesis of unrestricted evolution; but he applies the method of scientific procedure within his selected province of inquiry. Evolution is for him a doctrine of descent in affiliated organisms.

In dealing with paleontological records of extinct animals, say of the horse-type, his snapshot evidence of 1, m, and n is neces sarily widely spaced. Intervening phases must be filled in by in ference. Let us suppose the "missing links" are such as may be inferred if a generalization based on the known 1, m, n be valid. The subsequent discovery of links heretofore missing adds to the probability of the generalization. The method of procedure is substantially that of interpolating observed points—the closer the better—on a curve of probability. The conditions are differ ent when the biologist deals, in terms of 1, m, n, with adults of three successive generations. Even here, however, there is a con siderable time-interval between the records of individuals that have reached the requisite stage of development. But when we turn to this individual development, snapshots may be taken at minimum intervals. Hence in embryology one comes to close quarters with next-to-next phases of advance. It then remains to correlate the story of individual development (ontogeny) with that of racial evolution (phylogeny).

Turning now to what one may speak of as linear genetics one brings under observation a short span of a germinal line of ad vance—or, under gametic union the relational intersection of two such lines—stretching back to more and more primitive organ isms. Here, too, the aim is to get next-to-next phases in advance at minimum interval, to be interpreted in terms of relations extrinsic and intrinsic.

Biochemical Evolution.

In the method of treatment here adopted for expository purposes any three phases or stages of evolutionary advance are symbolized by 1, in, and ii. In all exact and detailed inquiry one's aim is to get recorded steps at minimum time-interval. Then, by combining synthetically a great number of sequent stages, thus analytically distinguished, one may en visage a cinema picture of the advance of events in nature.

If one take snapshot records at very wide intervals, say near the beginning, in the central region, and at the end (so far) of the whole evolutionary process, our 1 may stand for the atom, our m for the amoeba, our n for man. In the specialized field of biological inquiry, all that lies below the living organism is ex cluded. But in a specialized branch of biochemical research the aim is to ascertain whether, under laboratory conditions, there can be traced an evolutionary passage from the not-living to the living. If i be the not-living and n the living, the task of the bio chemist (or part of his task) is to find the transitional steps which fall under in. The full sequence has not yet been found. What progress has been made in the seeking cannot here be sum marized, since our aim is only to indicate the method of pro cedure ; to emphasize the importance of recording next-to-next snapshots ; and to show how, from a wide array of such records, a cinema picture may be constructed.

Mental Evolution.—The biologist and the biochemist tell us what happens when relations of the physical kind are in being. The specific "modes" of relatedness differ at different stages of the onward passage of events in evolutionary progress—atomic, molecular, and organic. Such difference as is in evidence, for ex ample, in thy living as contrasted with the not-living, must be duly formulated and loyally accepted. The canon of scientific interpretation runs : Given such and such modes of relatedness; such and such is the course of events.

In mental evolution relations of a different kind—relations other than physical or physiclogical, but none the less natural relations—must receive full consideration, and must be corre lated with such physical relations as are judged to be co-present. But just as there are ascending modes of physical and physiologi cal relatedness so are there ascending modes of mental related ness. When this or that higher mode is in being, the course of events differs from that which is observed when the mode of re latedness has not come into being in evolutionary progress.

That which may be inferred from observation is still interpret able in terms of 1, m and n, which now carry two-fold import, both physical and mental. In our own current experience, complex as this is, the aim of psychological analysis is to get as near as one can to next-to-next steps. But, under wide spacing, if 1 be the life-mind stage of an amoeba, rn that of a rabbit, 7a that of a man, one should not interpret in in terms of n, which is more highly evolved ; nor should one interpret m in terms of l—or in these terms only—because what gives to m its evolutionary status com prises more than is comprised under 1. One should take in as one finds it at its own level. Thus one may say (a) in mental and in (b) physical regard (which provides for energy changes) : Given such and such mode of relatedness extrinsic or intrinsic ; such and such is the course of events in this or that instance of 1, m or n. The same method of interpretation is applicable throughout nature. There is no privileged field of natural events wherein its writ does not run.

Restricted Evolution.—It remains briefly to indicate the cardinal claim of those who advocate a restricted use of the word "evolution." This claim is that a concept of agency, as efficient cause, is imperatively demanded when one passes the mechanical world of the not-living to the purposive realm of the living. On this all other claims hinge. A further claim—that here in focus- is that only when Life enters into, possesses, organizes and uti lizes a physical cluster of events, is there evolution in that sense to which, as they urge, it should be restricted. There is, it is said, nothing in common, between cosmic or physical evolution, so called, and the uplifting activity of Mind disclosed in biologi cal evolution. This may therefore, in elliptical phrase, be spoken of as Creative—more strictly as implying creative activity.

Here the question arises : Is treatment in terms of creative activity—thus restricted to the purposive realm of the living— scientific or metaphysical? The answer turns on definitions. Some so characterize the domain of science as to exclude from its purview the concept of activity as efficient cause. Others urge that it must be included in biology. Opinions differ. That of M. Bergson may here be cited. "La philosophie" he says, "devra done suivre la science, pour superposer a la verite scientifique une connaissance d'un autre genre, qu'on pourra appeler meta physique." In science, he tells us, we are "dealing only with the evolved, which is a result, and not with evolution itself, which is the act by which the result is obtained.

It seems, then, we must take into consideration (r) an ob servable course of natural events ; (2) an interpretation of these events in terms of relations, intrinsic and extrinsic; (3) an ex planation of some of these events in terms of agency and act.

Fully admitting that under the third heading an important philosophical problem falls for discussion, one may hold that those who impose any restriction of the range of efficient causality must argue their case at the bar of philosophy. In the foregoing sections the field covered by the first and second heading has been selected as the universe of discourse. As we have seen there is, under these headings, ample provision for mental relations in all their ascending modes, and therefore for mental evolution. But it should be realized that for those who use the word "evolu tion" in the restricted sense, mental evolution implies far more than this. It implies Life or Mind as the efficient cause of the course of events in living creatures. But even if some such philosophical implication be accepted—or preferably one less restricted in scope—the interpretation of all natural events in relational terms must still be the aim of the man of science in his detailed investigations. (See ANIMAL BEHAVIOUR ; PSY CHOLOGY, COMPARATIVE.) (C. Li,. M.)