"To sum up. If the materialist affirms that the universe and all its phenomena are resolvable into matter and motion, Berkeley replies, True; but what you call matter and motion are known to us only as forms of consciousness; their being is to be conceived or known; and the existence of a state of consciousness, apart from a thinking mind, is a contradiction in terms. I conceive that this reasoning is irrefragable. And therefore, if I were obliged to choose between absolute materialism and absolute idealism, I should feel compelled to accept the latter alternative. Indeed, upon this point Locke does, practically, go as far in the direction of idealism as Berkeley, when he admits that the 'simple ideas which we receive from sensation and reflection are the boundaries of our thoughts, beyond which the mind, whatever efforts it would make, is not able to advance one jot.'" Locke went further, and Huxley agreed with him. He declared that the mind cannot "make any discoveries when it would pry into the nature and hidden cause of these ideas." We must, in fact, definitely reject what we know as matter as the absolute reality of the universe, for it becomes very plain that what we call matter we know merely as affections of our own consciousness. In a sense, then, so far as it is opposed to materialism, idealism, according to Huxley, must be the philosophical position of a scientific man. But the idealism is not the absolute idealism of Berkeley, as we have no logical right to deny or to affirm the existence of absolute matter or of absolute mind. The real truth of the philosophy of science lies in a separation between metaphysical theory and actual pursuits. In ultimate philosophical theory it is impossible to rest content with a plain natural conception of the universe. When any conception of matter, or of its affections, is pushed as far as analysis can take us, what we know resolves itself into affections of mind, into what without metaphysical finesse may be called ideas. But this empirical idealism must be taken positively as being merely the limits of our knowledge, and it must carry with it neither an undue exaltation of mind nor an undue depreciation of matter. "The Platonic philosophy is probably the grandest example of the unscientific use of the imagination extant; and it would be hard to estimate the amount of detriment to clear thinking effected, directly and indirectly, by the theory of ideas, on the one hand, and by the unfortunate doctrine of the baseness of matter, on the other."