This law of evolution also applies to the art of writing, which is at first only the precise copy of the image; it is next transformed into an analogous symbol, and then into an alphabetical sign, which serves as the simple expression of the conception, divested of its originally representative faculty. Hence it is apparent that the evolution of myth conforms to the general law of the evolution of human thought, of all its products and arts in their manifold ramifications. From the image, the informing subject, from the conception and the myth, the necessary cycle is accomplished in regular phases, wherever the ethnic temperament and capacity and extrinsic circumstances permit it, until the rational idea is reached, the sign or cipher which becomes the powerful instrument of the exercise and generalization of thought. In order to show the efficacy of the mythical and scientific faculty of thought comprised in the systems of ancient and modern philosophy, and its slow progress towards positive and rational science, we will adduce an instance from the people in whom such an evolution was accomplished, aided by all the civilized peoples in reciprocal communication with them. Let us see how this faculty was manifested in the Greeks at a time when they first attempted to reduce the earlier and scanty knowledge of nature to a system. In Greece the historical course of this faculty ramified into two classes of research, which were at that time objective, the Ionic and the Pythagorean schools. In the former, the phenomenon and nature were assumed to be the direct object of knowledge, while in the latter the object in view was the idea and harmony of things. Influenced by earlier and popular traditions, a mythical and philosophic system arose in the Ionic school, which was exclusively devoted to physical speculations. In Lower Italy, on the contrary, and in colonies which were for the most part Doric, a science was constituted which, although it included physics and natural phenomena, did not only consider their material value, but sought to extract from their laws and harmony a criterion of good and evil. Ritter observes that the intimate connection between the Pythagorean philosophy and lyrical music--of which the origin was sought as a clue to explain the world--shows how far this philosophy was consonant with Doric thought. This historic process is quite natural, since the speculations of philosophy are first directed to physical phenomena, as they are displayed in inward and in external life, and then rise to the consideration of specific types, in a word, to the general and the universal.