But science does not merely consist in the systematic arrangement of facts in which it begins, nor in their combination into general and comprehensive laws; the sequence of causes and effects must also be understood, and it is not enough to classify the fact without explaining its genesis and cause. We have seen that the innate faculty of perception involved the idea of a cause in the supposition that the phenomenon was actuated by a subject, and while thought classified fetishes and idols in a mythical way, an inherent power for good or evil was ascribed to them, not only in their relation to man, but in their effects on nature. What Vico has called "the poetry of physics" consisted in the explanation of natural phenomena by the efficacy of mythical and supernatural agents. From this point of view again, myth and science pursue identically the same method and the same general form of cognition. Nor is this all. Science is, in fact, the _de-personification_ of myth, arriving at a rational idea of that which was originally a fantastic type by divesting it of its wrappings and symbols. In the natural evolution of myth, man passes from the extrinsic mythical substance to the intrinsic ideal by the same intellectual process, and when the types have become ideas, he carries on intrinsically the _entifying_ process which he first applied to the material and external phenomena. In this case also the process is gradual; by attempting a more rational explanation of physical phenomena, man attains to ultimate conceptions which express direct cosmic laws, and he regards these laws as substantial entities, which in their originally polytheistic form were the gods who directed all things. Here the scientific myth really begins, since natural forces and phenomena are no longer personified in anthropomorphic beings; but the laws or general principles of physics are transformed into material subjects, which are still analogous to human consciousness and tendencies, although the idolatrous anthropomorphism has disappeared. The combination of myth and science in the human mind does not stop here, since, as I have said, it goes on to form ideal representations. When thought penetrates more deeply into the physical laws of the universe, and is also more rationally engaged in the psychical examination of man's own nature, ideas are classified in more general types, as in the primitive construction of fetishes, anthropomorphic idols, and physical principles; and in this way an explicit and purely ideal system is formed, in which the images correspond with the fanciful and physical types which were previously created.