Elements of metaphysics

by A. E. Taylor

CHAPTER V
SOME CONDITIONS OF EVOLUTION

[§ 1.] The concept of evolution an attempt to interpret natural processes in terms of individual growth. [§ 2.] Evolution means change culminating in an end which is the result of the process and is qualitatively new. The concept is thus teleological. [§ 3.] Evolution, being teleological, is essentially either progress or degeneration. If it is more than illusion, there must be real ends in the physical order. And ends can only be real as subjective interests of sentient beings which are actualised by the process of change. [§ 4.] Thus all evolution must take place within an individual subject. [§ 5.] Further, the subject of evolution must be a finite individual. All attempts to make “evolution” a property of the whole of Reality lead to the infinite regress. [§ 6.] The distinction between progressive evolution and degeneration has an “objective” basis in the metaphysical distinction between higher and lower degrees of individuality. [§ 7.] In the evolutionary process, old individuals disappear and fresh ones originate. Hence evolution is incompatible with the view that Reality consists of a plurality of ultimately independent finite individuals.

§ 1. We saw, in the first chapter of the present Book, that evolution or orderly development is a fundamental characteristic of the processes which compose the physical order as apprehended by the various empirical sciences. For the purposes of Mechanics and Mechanical Physics, indeed, we have no need to look upon Nature as the scene of development; for these sciences it is enough to conceive of it as a vast complex of changes of configuration and transformations of energy, connected by regular uniformities of sequence. As soon, however, as we come to regard Nature from the standpoint of those sciences which explicitly recognise differences of quality, as well as differences in position and quantity, among the objects with which they deal, this narrowly mechanistic conception of natural processes becomes inadequate. With the notion of physical processes as productive of changes of quality we are inevitably led to think of the physical order as a world in which the qualitatively new is derived from, or developed out of, the previously familiar by fixed lines of deviation and under determinate conditions.

Naturally enough, it is from the biological sciences, in which the study of organic growth plays so prominent a part, that the impulse to conceive of physical change as development originally comes. As long ago as the fourth century B.C., Aristotle had taken the concept of growth or development as the foundation of the most influential scheme of metaphysical construction yet produced in the whole history of speculation. In Aristotle’s view, however, the process of development was regarded as strictly confined within the limits of the individual life. The individual organism, beginning its existence as an undeveloped germ or potentiality, gradually unfolds itself in a series of successive stages of growth, which culminates at the period of complete maturity. But the individual germ itself is a product or secretion derived from a pre-existing mature individual of the same type as that into which this germ will ultimately grow. The number of distinct typical processes of growth is thus strictly determined, and each such process implies the previous existence of its completed result. In other words, the boundaries between species are fixed and ultimate; there can be no beginning in time of the existence of a new species, and therefore no origination of new species by development from other types. As Aristotle epigrammatically puts it, “It takes a man to beget a man.”

A further point of weakness in the Aristotelian theory is the absence of any definite account of the machinery by which the process of growth is effected. We learn, indeed, that the latent capacity of the organic germ to develop according to a certain specific type is stimulated into activity by influences contained in the environment, but the precise nature of this process of stimulation was necessarily left in obscurity, in consequence of the imperfect knowledge possessed by Aristotle of the minute character of natural processes in general.

In the evolutionary theories of modern biology, it is precisely the problems of the origination of new species, and of the special character of the relations between the species and its environment by which this process is conditioned, that have attracted almost exclusive attention. And, with the steadily increasing success of evolutionary hypotheses in dealing with biological problems, there has naturally arisen a tendency to extend the application of the general concept of evolution far beyond the sphere in which it first originated. We have now not only more or less well-accredited hypotheses of the production by evolution of our chemical elements, but even ambitious philosophical constructions which treat the concept of evolution as the one and only key to all the problems of existence. In the presence of these far-reaching applications of evolutionary ideas, it becomes all the more necessary to bear in mind, in our estimate of the worth of the evolution concept, that its logical character remains unaltered by the extension of its sphere of applicability; it is still, in spite of all minor modifications, essentially an attempt to interpret natural processes in general in terms of individual growth.

We are not, of course, in the present chapter in any way concerned with the details of any one particular theory as to the special conditions which determine the course of organic or other evolution. What those conditions in any special case are, is a question, in the first instance, for that particular branch of empirical science which deals with the description of the particular aspect of the processes of the physical order under investigation. And though it would be a proper question for a complete Philosophy of Nature how the details of a well-established scientific theory must be interpreted so as to harmonise with the general metaphysical implications of the physical order, it is for many reasons premature to raise such a question in the present state of our actual knowledge of the details of evolutionary processes. All that can be done here is to ask what in general are the logical implications involved in thinking of a process as an evolution at all, and how those implications are related to our general interpretation of the physical order.

§ 2. Evolution obviously involves the two concepts, already criticised at length, of change and the dependence of the order and direction of change upon determinate conditions. But an evolutionary process is never a mere orderly sequence of changes. For instance, the changes of configuration and exchanges of energy which take place when work is done in a material system, conceived as composed of moving masses without any element of secondary quality, are not properly to be called a process of evolution. They are not an evolution or development, because, so long as we keep to the strictly kinetic view of natural processes as consisting solely in the varying configuration of systems of mass-particles, the end of the process is qualitatively undistinguishable from its beginning; nothing qualitatively new has emerged as its result. Or rather, to speak with more accuracy, the process has really no end and no unity of its own. It is only by an entirely arbitrary limitation of view, due to purely subjective interests of our own, that we isolate just this collection of mass-particles from the larger aggregate of such particles which form the physical order as regarded from the strictly kinetic standpoint, and call it one system; and again, it is with equal arbitrariness that we determine the point of time beyond which we shall cease to follow the system’s changes of configuration. In the indefinitely prolonged series of successive configurations there is no stage which can properly be called final. Hence from the rigidly mechanistic point of view of Kinetics and Kinematics there are no evolutions or developments in the universe, there is only continuous change.

Development or evolution, then, definitely implies the culmination of a process of change in the establishment of a state of things which is relatively new, and implies, further, that the relatively new state of things may truly be regarded as the end or completion of this special process of change. Thus the fundamental peculiarity of all evolutionary ideas is that they are essentially teleological; the changes which are evolutions are all changes thought of as throughout relative to an end or result. Except in so far as a process of change is thus essentially relative to the result in which it culminates, there is no sense in calling it a development. We may see this even by considering the way in which the concepts of evolution and development are used in the various departments of Physics. We sometimes speak of a chemical process as marked by the “evolution” of heat, or again we say that, if the second law of Thermo-dynamics is rigidly and universally true, the physical universe must be in a process of evolution towards a stage in which none of its energy will be available for work. But we can only attach a meaning to such language so long as we allow ourselves to retain the common-sense point of view according to which there are real qualitative differences between what abstract Mechanics treats as equivalent forms of “energy.”

We can speak of the evolution of heat, just because we, consciously or unconsciously, think of heat as being really, what it is for our senses, something qualitatively new and distinct from the other kinds of energy which are converted into it by the chemical process. So we can intelligibly talk of the gradual conversion of one form of energy into another as an evolution only so long as we regard the various forms of energy as qualitatively different, and are therefore entitled to look upon the complete conversion of the one into another as the qualitatively new result of a process which is therefore terminated by its complete establishment. From the standpoint of the physical theories which regard the distinction between the forms of energy as only “subjective,” there would be no sense in regarding that particular stage in the course of events at which one form of energy disappeared as the end or result of a process which terminates in it, and thus such terms as evolution and development would lose their meaning. Only the establishment of the qualitatively new can form a real end or result, and so afford a logical basis for the recognition of the changes in the physical order as distinct processes of development.