could not, of course, deny that individual living things come into existence and gradually grow to maturity; but he insists that their formation is teleologically determined by the parental type which they are striving to realise. He asks whether we should study a thing by examining how it grows, or by examining its completed form: and Mr. Wallace quotes the question without quoting the answer.[203] Aristotle tells us that the genetic method was followed by his predecessors, but that the other method is his. And he goes on to censure Empedocles for saying that many things in the animal body are due simply to mechanical causation; for example, the segmented structure of the backbone, which that philosopher attributes to continued doubling and twisting—the very same explanation, we believe, that would be given of it by a modern evolutionist.[204] Finally, Aristotle assumes the only sort of transformation which we deny, and which Democritus equally denied—that is to say, the transformation of the ultimate elements into one another by the oscillation of an indeterminate matter between opposite qualities. VI. The truth is that while our philosopher had one of the most powerful intellects ever possessed by any man, it was an intellect strictly limited to the surface of things. He was utterly incapable of divining the hidden forces by which inorganic nature and life and human society are moved. He had neither the genius which can reconstruct the past, nor the genius which partly moulds, partly foretells the future. But wherever he has to observe or to report, to enumerate or to analyse, to describe or to define, to classify or to compare; and whatever be the subject, a mollusc or a mammal, a mouse or an elephant; the structure and habits of wild animals; the different stages in the development of an embryo bird; the variations of a single organ or function through the entire zoological series; the hierarchy of intellectual faculties; the laws of mental association; the specific types of virtuous character; the relation of equity to law; the relation of reason to impulse; the ideals of friendship; the different members of a household; the different orders in a State; the possible variations of political constitutions, or within the same constitution; the elements of dramatic or epic poetry; the modes of predication; the principles of definition, classification, judgment, and reasoning; the different systems of philosophy; all varieties of passion, all motives to action, all sources of conviction;—there we find an enormous accumulation of knowledge, an unwearied patience of research, a sweep of comprehension, a subtlety of discrimination, an accuracy of statement, an impartiality of decision, and an all-absorbing enthusiasm for science, which, if they do not raise him to the supreme level of creative genius, entitle him to rank a very little way below it.