Spencer’s own materialistic definition of evolution; otherwise there
will be a break at least between life and mind. If everything knowable
is an example of evolution, and evolution is by definition a
transformation of matter and motion, then everything knowable
is an example of a transformation of matter and motion. As an
exponent of universal evolution Haeckel is more consistent than
Spencer.
Huxley (1825–1895) developed views very like those of Spencer, and similarly materialistic without being materialism, because inconsistent. He regarded everything known as evolved from matter, and reduced consciousness to a mere collateral product (“epiphenomenon”) of cerebral operations without any power of influencing them. Matter, according to him, impresses the afferent Huxley. nervous system, this the brain, this the efferent nervous system, while consciousness remains a mere spectator. “In man, as in brutes,” said he, “there is no proof that any state of consciousness is the cause of change in the nature of the matter of the organism”; so that “we are conscious automata.” But, in spite of these materialistic tendencies, he followed Hume in reducing matter and everything knowable to phenomena of consciousness; and, supposing that nothing is knowable beyond phenomena, concluded that we can neither affirm nor deny that anything exists beyond, but ought to take up an attitude which the ancient sceptics called Aphasia, but he dubbed by the new name of Agnosticism. Thus Huxley first reduced consciousness to a product of matter, and then matter to a phenomenon of consciousness. By combining materialism with idealism he made consciousness a product of itself. Tyndall (1820–1893), Tyndall. again, came still nearer to materialism, and yet avoided it. In his Belfast address (1874), while admitting that matter as understood by Democritus is insufficient, because atoms without sensation cannot be imagined to produce sensation, he contended, nevertheless, that matter properly understood is “the promise and potency of all terrestrial life.” In thus endowing all matter with sensation like Haeckel he was not avoiding materialism. But in the very same address, as well as on other occasions, he did not identify mind with matter, but regarded them as concomitant.
All these materialistic tendencies seem to have one explanation. They emanate from scientific writers who rightly try to rise from science to metaphysics, but, as Bacon says, build a universal philosophy on a few experiments. The study of evolution, without considering how many conditions are required for “the integration of matter and the dissipation of motion” to begin, and the undoubted discoveries which have resulted from the study of inorganic and organic evolution, have led men to expect too much from this one law of Nature. This tendency especially prevails in biology, which is so far off the general principles of natural philosophy that its votaries are often ignorant of the real nature of body as matter and force. The close dependency of all mental operations on brain also tempts them to the conclusion that brain is not only an organ, but the whole organ of conscious mind.[1] It appears also that Darwin, having extended his theory of evolution as far as the rational and moral nature of man, in the Descent of Man, ended in his Autobiography by declaring his attitude to first and final causes to be that of an agnostic. Not that he was a materialist, and shortly before his death, in a conversation with Büchner, he maintained his agnosticism against his opponent’s atheism. Still, his agnosticism meant that, though he did not assert that there is no God, he did assert that we cannot know whether there is or is not. To the evolutionary biologist brain is apt to appear to be the crowning object of knowledge. On the other hand, scientific men, such as Herschel, Maxwell and Stokes, who approach nature from mathematics and mechanics, and therefore from the universal laws of motion, have the opposite tendency, because they perceive that nature is not its own explanation. In order to exert force, or at all events that force of reciprocal pressure which we best understand, and on which, in impact, the third law of motion was founded, there are always at least two bodies, enduring, triply extended, mobile, each inert, mutually impenetrable or resistent, different yet similar; and in order to have produced any effect but equilibrium, some bodies must at some time have differed either in mass or in velocity, otherwise forces would only have neutralized one another. Why do bodies exist, with all these conditions, so similar yet different—that is, in so harmonious an order? Natural science has no answer: natural theology has an answer. This essence of bodies, this resemblance in difference, this prevailing order of Nature, is the deepest proof of God; and it cannot be the result of evolution, because it is the condition of natural force, and therefore of natural evolution. A second argument for God is the prevailing goodness or adaptation of Nature to the ends of conscious beings, which might conceivably be explained by Lamarckian evolution, but has not yet been so explained, and if it were, would not be inconsistent with a divine design in evolution. Further, the very existence of conscious beings is the best proof of the distinct or substantial being of the soul, existing in man with body, in God as pure spirit. It seems hopeless to expect that natural science, even with the aid of evolution, can explain by mere body the origin and nature of this fact of consciousness. If so, materialism is not the whole truth of metaphysics.
3.—The Rise of Metaphysical Idealism
1. Descartes to Leibnitz.—Metaphysical arises from psychological idealism, and always retains more or less of an epistemological character. Psychological idealism assumes without proof that we perceive nothing but mental objects, and metaphysical idealism draws the logical but hypothetical conclusion that all we can know from these mental objects of sense is mental objects of knowledge. But at first this logical conclusion was not drawn. Descartes, the founder of psychological idealism, having proceeded from the conscious fact, cogito ergo sum, to the non sequitur that I am a soul, and all a soul can perceive is Descartes. its ideas, nevertheless went on to the further illogical conclusion that from these mental ideas I can (by the grace of God) infer things which are extended substances or bodies, as well as thinking substances or souls. He was a psychological idealist and a metaphysical realist. This illogicality could not last. Even the Cartesian school, as it came more and more to feel the difficulty of explaining the interaction of body and mind, and, indeed, any efficient causation whatever, gradually tended to the hypothesis that the real cause is God, who, on the occasion of changes in body, causes corresponding changes in mind, and vice versa. This occasionalism is not idealism, but its emphasis on the will of God gave it an idealistic tendency. Thereupon Spinoza advanced a pantheism which supposed that bodies and souls are not, as Descartes thought, different substances, but merely attributes—the one the extension and the other the thought of one substance, Nature or God. Taking the Spinoza. Aristotelian theory that a substance is a thing in itself, not in Aristotle’s sense of any individual existing differently from anything else, but in the novel meaning of something existing alone, he concluded, logically enough from this mere misunderstanding, that there can be only one substance, and that, as no finite body or soul can exist alone, everything finite is merely a mode of one of the attributes of the one infinite substance which alone can exist by itself. Spinozism, however, though it tramples down the barrier between body and soul, is not yet metaphysical idealism, because it does not reduce extension to thought, but only says that the same substance is at once extended and thinking—a position more akin to materialism. At the same time Spinoza maintained a parallelism between extension and thinking so close as to say that the order of ideas is the same as the order of things, so that any mode of extension and the idea of it are the same thing expressed in two ways, under the attribute of extension and under the attribute of thought (see H. H. Joachim’s Study of the Ethics of Spinoza, 1901, p. 72). It remained, however, for Schelling to convert this parallelism into identity by identifying motion with the intelligence of God, and so to transform the pantheism of Spinoza into pantheistic idealism. Leibnitz, again, having become equally dissatisfied with Cartesianism, Spinozism and the Epicurean realism of Leibnitz. Gassendi, in the latter part of his life came still nearer than Spinoza to metaphysical idealism in his monadology, or half-Pythagorean, half-Brunistic analysis of bodies into monads, or units, or simple substances, indivisible and unextended, but endowed with perception and appetite.
He gradually fell under the dominion of two false assumptions. On the one hand, essentially a mathematician, he supposed that
- ↑ Cf. H. Maudesley, Lessons of Materialism (1879).