If we watch, e.g. the growth of a tree we perceive that its various parts are not isolated and unconnected, but that on the contrary they are only possible by reference to the idea of the whole. Each limb affects every other, and is reciprocally affected by it; in short “in such a product of nature every part not only exists by means of the other parts, but is thought as existing for the sake of the others and the whole” (p. 277). The operations of nature in organised bodies seem to be of an entirely different character from mere mechanical processes; we cannot construe them to ourselves except under the hypothesis that nature in them is working towards a designed end. The distinction between nature’s “Technic” or purposive operation, and nature’s Mechanism is fundamental for the explanation of natural law. The language of biology eloquently shows the impossibility of eliminating at least the idea of purpose from our investigations into the phenomena of life, growth, and reproduction. And Kant dismisses with scant respect that cheap and easy philosophy which would fain deny the distinctiveness of nature’s purposive operation. A doctrine, like that of Epicurus, in which every natural phenomenon is regarded as the result of the blind drifting of atoms in accordance with purely mechanical laws, really explains nothing, and least of all explains that illusion in our teleological judgements which leads us to assume purpose where really there is none.
It has been urged by Kirchmann and others that this distinction between Technic and Mechanism, on which Kant lays so much stress, has been disproved by the progress of modern science. The doctrines, usually associated with the name of Darwin, of Natural Selection and Survival of the Fittest, quite sufficiently explain, it is said, on mechanical principles the semblance of purpose with which nature mocks us. The presence of order is not due to any purpose behind the natural operation, but to the inevitable disappearance of the disorderly. It would be absurd, of course, to claim for Kant that he anticipated the Darwinian doctrines of development; and yet passages are not wanting in his writings in which he takes a view of the continuity of species with which modern science would have little fault to find. “Nature organises itself and its organised products in every species, no doubt after one general pattern but yet with suitable deviations, which self-preservation demands according to circumstances” (p. 279). “The analogy of forms, which with all their differences seem to have been produced according to a common original type, strengthens our suspicions of an actual relationship between them in their production from a common parent, through the gradual approximation of one animal genus to another—from those in which the principle of purposes seems to be best authenticated, i.e. from man, down to the polype and again from this down to mosses and lichens, and finally to crude matter. And so the whole Technic of nature, which is so incomprehensible to us in organised beings that we believe ourselves compelled to think a different principle for it, seems to be derived from matter and its powers according to mechanical laws (like those by which it works in the formation of crystals)” (p. 337). Such a theory he calls “a daring venture of reason,” and its coincidences with modern science are real and striking. But he is careful to add that such a theory, even if established, would not eliminate purpose from the universe; it would indeed suggest that certain special processes having the semblance of purpose may be elucidated on mechanical principles, but on the whole, purposive operation on the part of Mother Nature it would still be needful to assume (p. 338). “No finite Reason can hope to understand the production of even a blade of grass by mere mechanical causes” (p. 326). “It is absurd to hope that another Newton will arise in the future who shall make comprehensible by us the production of a blade of grass according to natural laws which no design has ordered” (p. 312).
Crude materialism thus affording no explanation of the purposiveness in nature, we go on to ask what other theories are logically possible. We may dismiss at once the doctrine of Hylozoism, according to which the purposes in nature are explained in reference to a world-soul, which is the inner principle of the material universe and constitutes its life. For such a doctrine is self-contradictory, inasmuch as lifelessness, inertia, is the essential characteristic of matter, and to talk of living matter is absurd (p. 304). A much more plausible system is that of Spinoza, who aimed at establishing the ideality of the principle of natural purposes. He regarded the world whole as a complex of manifold determinations inhering in a single simple substance; and thus reduced our concepts of the purposive in nature to our own consciousness of existing in an all-embracing Being. But on reflection we see that this does not so much explain as explain away the purposiveness of nature; it gives us an unity of inherence in one Substance, but not an unity of causal dependence on one Substance (p. 303). And this latter would be necessary in order to explain the unity of purpose which nature exhibits in its phenomenal working. Spinozism, therefore, does not give what it pretends to give; it puts us off with a vague and unfruitful unity of ground, when what we seek is a unity that shall itself contain the causes of the differences manifest in nature.
We have left then as the only remaining possible doctrine, Theism, which represents natural purposes as produced in accordance with the Will and Design of an Intelligent Author and Governor of Nature. This theory is, in the first place, “superior to all other grounds of explanation” (p. 305), for it gives a full solution of the problem before us and enables us to maintain the reality of the Zweckmässigkeit of nature. “Teleology finds the consummation of its investigations only in Theology” (p. 311). To represent the world and the natural purposes therein as produced by an intelligent Cause is “completely satisfactory from every human point of view for both the speculative and practical use of our Reason” (p. 312). Thus the contemplation of natural purposes, i.e. the common Argument from Design, enables us to reach a highest Understanding as Cause of the world “in accordance with the principles of the reflective Judgement, i.e. in accordance with the constitution of our human faculty of cognition” (p. 416).
It is in this qualifying clause that Kant’s negative attitude in respect of Theism betrays itself. He regards it as a necessary assumption for the guidance of scientific investigation, no less than for the practical needs of morals; but he does not admit that we can claim for it objective validity. In the language of the Critique of Pure Reason, the Idea of God furnishes a regulative, not a constitutive principle of Reason; or as he prefers to put it in the present work, it is valid only for the reflective, not for the determinant Judgement. We are not justified, Kant maintains, in asserting dogmatically that God exists; there is only permitted to us the limited formula “We cannot otherwise conceive the purposiveness which must lie at the basis of our cognition of the internal possibility of many natural things, than by representing it and the world in general as produced by an intelligent cause, i.e. a God” (p. 312).
We ask then, whence arises this impossibility of objective statement? It is in the true Kantian spirit to assert that no synthetical proposition can be made with reference to what lies above and behind the world of sense; but there is a difficulty in carrying out this principle into details. Kant’s refusal to infer a designing Hand behind the apparent order of nature is based, he tells us, on the fact that the concept of a “natural purpose” is one that cannot be justified to the speculative Reason. For all we know it may only indicate our way of looking at things, and may point to no corresponding objective reality. That we are forced by the limited nature of our faculties to view nature as working towards ends, as purposive, does not prove that it is really so. We cannot justify such pretended insight into what is behind the veil.
It is to be observed, however, that precisely similar arguments might be urged against our affirmation of purpose, design, will, as the spring of the actions of other human beings.[3] For let us consider why it is that, mind being assumed as the basis of our own individual consciousness, we go on to attribute minds of like character to other men. We see that the external behaviour of other men is similar to our own, and that the most reasonable way of accounting for such behaviour is to suppose that they have minds like ourselves, that they are possessed of an active and spontaneously energising faculty, which is the seat of their personality. But it is instructive to observe that neither on Kantian principles nor on any other can we demonstrate this; to cross the chasm which separates one man’s personality from another’s requires a venture of faith just as emphatically as any theological formula. I can by no means prove to the determinant Judgement that the complex of sensations which I constantly experience, and which I call the Prime Minister, is anything more than a well-ordered machine. It is improbable that this is the case—highly improbable; but the falsity of such an hypothesis cannot be proved in the same way that we would prove the falsity of the assertion that two and two make five. But then though the hypothesis cannot be thus ruled out of court by demonstration of its absurdity, it is not the simplest hypothesis, nor is it that one which best accounts for the facts. The assumption, on the other hand, that the men whom I meet every day have minds like my own, perfectly accounts for all the facts, and is a very simple assumption. It merely extends by induction the sphere of a force which I already know to exist. Or in other words, crude materialism not giving me an intelligent account of my own individual consciousness, I recognise mind, νοῦς, as a vera causa, as something which really does produce effects in the field of experience, and which therefore I may legitimately put forward as the cause of those actions of other men which externally so much resemble my own. But, as has been said before, this argument, though entirely convincing to any sane person, is not demonstrative; in Kantian language and on Kantian principles the reasoning here used would seem to be valid only for the reflective and not for the determinant Judgement. If the principle of design or conscious adaptation of means to ends be not a constitutive principle of experience, but only a regulative principle introduced to account for the facts, what right have we to put it forward dogmatically as affording an explanation of the actions of other human beings?
It cannot be said that Kant’s attempted answer to such a defence of the Design Argument is quite conclusive. In § 90 of the Methodology (p. 399) he pleads that though it is perfectly legitimate to argue by analogy from our own minds to the minds of other men,—nay further, although we may conclude from those actions of the lower animals which display plan, that they are not, as Descartes alleged, mere machines—yet it is not legitimate to conclude from the apparent presence of design in the operations of nature that a conscious mind directs those operations. For, he argues, that in comparing the actions of men and the lower animals, or in comparing the actions of one man with those of another, we are not pressing our analogy beyond the limits of experience. Men and beasts alike are finite living beings, subject to the limitations of finite existence; and hence the law which governs the one series of operations may be regarded by analogy as sufficiently explaining the other series. But the power at the basis of Nature is utterly above definition or comprehension, and we are going beyond our legitimate province if we venture to ascribe to it a mode of operation with which we are only conversant in the case of beings subject to the conditions of space and time. He urges in short that when speaking about man and his mind we thoroughly understand what we are talking about; but in speaking of the Mind of Deity we are dealing with something of which we have no experience, and of which therefore we have no right to predicate anything.
But it is apparent that, as has been pointed out, even when we infer the existence of another finite mind from certain observed operations, we are making an inference about something which is as mysterious an x as anything can be. Mind is not a thing that is subject to the laws and conditions of the world of sense; it is “in the world but not of the world.” And so to infer the existence of the mind of any individual except myself is a quite different kind of inference from that by which, for example, we infer the presence of an electro-magnet in a given field. The action of the latter we understand to a large extent; but we do not understand the action of mind, which yet we know from daily experience of ourselves does produce effects in the phenomenal world, often permanent and important effects. Briefly, the action of mind upon matter (to use the ordinary phraseology for the sake of clearness) is—we may assume for our present purpose—an established fact. Hence the causality of mind is a vera causa; we bring it in to account for the actions of other human beings, and by precisely the same process of reasoning we invoke it to explain the operations of nature.
And it is altogether beside the point to urge, as Kant does incessantly, that in the latter case the intelligence inferred is infinite; in the former only finite. All that the Design Argument undertakes to prove is that mind lies at the basis of nature. It is quite beyond its province to say whether this mind is finite or infinite; and thus Kant’s criticisms on p. 364 are somewhat wide of the mark. There is always a difficulty in any argument which tries to establish the operation of mind anywhere, for mind cannot be seen or touched or felt; but the difficulty is not peculiar to that particular form of argument with which theological interests are involved.