indistinguishable from spirit, or, as Coleridge said in a similar connexion, 'a something-nothing-everything which does all of which we know '.1 It becomes, indeed, simply the notion of potentiality as such-perhaps the most slippery term in the whole vocabulary of philosophy. If it is the complete or final fact which we wish to explain, and if, as we have seen, explanation can only mean accurate description or analysis of the nature of the fact, it is clear that it can serve no useful purpose-it must, indeed, be fundamentally misleading-to say that characteristics which, according to the very meaning of the terms, are not exhibited by the atoms and molecules of the physicist, are potentially present in these particles as such. To insist in this way on regarding the later stages as existing preformed, so to speak, in the bare beginning is, as we have seen, to ignore the true nature of the evolution-process, as characterized by the emergence of real differences and the attainment of results which transcend the apparent startingpoint. It is only in so far as we connect the physical with the vital and the conscious, as stages of a single process, that we can speak, with even a show of intelligibility, of the physical as containing the potentiality of all that is to follow. The philosophical meaning of potentiality is, in short, simply the insight that, in the interpretation of any process, it is the process as a whole that has to be considered, if we wish to know the nature of the reality revealed in it. In other words, every evolutionary process must be read in the light of its last term. This is the true meaning of the profound Aristotelian doctrine of the Telos or End as the ultimate principle of explanation. As I have put it on a previous occasion—' All explanation of the higher by the lower is philosophically a hysteron-proteron. The antecedents assigned are not the causes of the consequents, for by antecedents the naturalistic theories mean the antecedents 1 Biographia Literaria, chap. vii. MEANING OF POTENTIALITY 107 in abstraction from their consequents—the antecedents taken as they appear in themselves, or as we might suppose them to be if no such consequents had ever issued from them. So conceived, however, the antecedents (matter and energy, for example), have no real existence-they are mere entia rationis, abstract aspects of the one concrete fact which we call the universe. All ultimate or philosophical explanation must look to the end. . . . If we are in earnest with the doctrine that the universe is one, we have to read back the nature of the latest consequent into the remotest antecedent. Only then is the one, in any true sense, the cause of the other.' 1 It is worth observing that the same apparently inveterate tendency to obliterate the distinctions between different ranges of experience may be seen asserting itself afresh in the relation of biology to psychology and sociology. Just as the long-established ascendancy of physical science has hindered the recognition of the autonomy of the science of life, imposing upon the biologist a foreign ideal, as if physical conceptions alone were ultimately valid—their de facto inadequacy in dealing with vital phenomena being attributed not to the characteristics of the subject-matter but to the biologist's (so far) imperfect analysis-in a similar fashion the prestige of biology has led within recent years to the wholesale application of biological conceptions and theories to the facts of mind and society. I do not wish to deny-I would, on the contrary, emphasize— the stimulus which psychology and sociology, as well as general philosophy, have derived from contact with the great biological movement of the last half-century. The biological analogies and metaphors are, in general, far more instructive than the physical conceptions which they replaced, and the restatement has made many phases of mental development more intelligible. But here again 1 Man's Place in the Cosmos, pp. 11-12. autonomy must be respected. Consciousness brings into view a new range of facts and values; and to suppose that biological categories can be more than suggestive analogies in the new sphere is once again to obliterate the distinctive characteristics of the facts which it is sought to describe. Loose talk about natural selection and the social organism will not solve the problems either of mental or of social science. A new order of facts demands its own conceptions in terms of which it may be described and systematized.1 From the philosophical point of view, therefore, explanation is essentially an affair of categories. Correct explanation depends in any department on the employment of appropriate categories, and philosophy consists in an insight into the relation of the categories in question and the realm of facts which they describe, to other categories and other realms or aspects of reality. We must have some notion of their significance in an account of the nature of the universe as a whole. The function of philosophy is, in this connexion, comparable to that of a Warden of the Marches' between the various sciences, resisting the pretensions of any particular science to be the exclusive exponent of reality and assigning to each its hierarchical rank in a complete scheme of knowledge. For if, as men of science tell us, scientific explanation is in the end description, the same is ultimately true of philosophy itself. Philosophy, or perhaps I should qualify the statement and say, sane philosophy, is not really the quest of some transcendent reason why the nature of things is as it is; it does not attempt, in Lotze's phrase, to tell us how being is made'. 'All that can be asked of philosophy', I ventured to say in my first volume, published more than thirty years ago, is, by the help of the most complete analysis, to present a reasonable synthesis of the world as 1 Cf. Ostwald, Natural Philosophy, p. 140 (English translation); Geddes and Thomson, Evolution, p. 231. V TRUE AND FALSE PHILOSOPHY 109 we find it. The difference between a true and a false philosophy is that a false philosophy fixes its eye on a part only of the material submitted to it, and would explain the whole, therefore, by a principle which is adequate merely to one of its parts or stages; a true philosophy, on the other hand, is one which "sees life steadily and sees it whole "-whose principle, therefore, embraces in its evolution every phase of the actual.'1 1 The Development from Kant to Hegel, p. 66. LECTURE VI MAN AS ORGANIC TO THE WORLD It is as between human intelligence and its antecedent conditions that the idea of a chasm or absolute break is most deeply rooted, both in philosophy and in ordinary thought. A variety of causes have contributed to create and perpetuate the impression. But if we consistently apply in this case the twin principles of continuity and immanence, and 1 steadily refuse to characterize the nature of the world till we have all the available facts before us, some of the most persistent difficulties of modern thought will be found, I think, to disappear. The nature of the power at work in any process, I urged in the preceding lecture, is only revealed in the process as a whole. It is revealed progressively in the different stages, but it cannot be fully and truly known till the final stage is reached, and it must inevitably lead to error if we substantiate any of the stages as something complete in itself and existing by itself. Now man-human knowledge and experience generally-is, from this point of view, the last term in the series, and the world is not complete without him. When I say the last term in the series, this does not involve any arrogant claim on man's part to 'set himself', in Locke's words, 'proudly at the top of all things'; in other mansions of the universe, as Locke quaintly puts it, 'there may be other and different intelligent beings, of whose faculties he has as little knowledge or apprehension as a worm shut up in one drawer of a cabinet hath of the senses or understanding of a man.'1 Man, himself, as we know 1 Essay, II. 2. 3. It is probably an unconscious reminiscence of this passage, when Huxley says (in a more sceptical interest) that we may be set down in the midst of infinite varieties of existences which we are not competent so much as to conceive-'with no more notion of what is |