The persons are put down in chronological order. This order will in some measure be preserved in the following survey; but regard for the continuity of the tradition of the doctrine will entail certain deviations. It will, that is to say, be natural to divide the material into four groups: the pre-Socratic philosophy; the Sophists; Socrates and the Socratics; Hellenistic philosophy. Each of these groups has a philosophical character of its own, and it will be seen that this character also makes itself felt in the relation to the gods of the popular belief, even though we here meet with phenomena of more isolated occurrence. The four groups must be supplemented by a fifth, a survey of the conditions in Imperial Rome. Atheists of this period are not found in our lists; but a good deal of old Pagan free-thinking survives in the first centuries of our era, and also the epithet _atheoi_ was bestowed generally on the Christians and sometimes on the Jews, and if only for this reason they cannot be altogether passed by in this survey. CHAPTER II The paganism of antiquity is based on a primitive religion, _i.e._ it is originally in the main homogeneous with the religions nowadays met with in the so-called primitive peoples. It underwent, however, a long process of evolution parallel with and conditioned by the development of Greek and later Roman civilisation. This evolution carried ancient religion far away from its primitive starting-point; it produced numerous new formations, above all a huge system of anthropomorphic gods, each with a definite character and personality of his own. This development is the result of an interplay of numerous factors: changing social and economical conditions evoked the desire for new religious ideas; the influence of other peoples made itself felt; poetry and the fine arts contributed largely to the moulding of these ideas; conscious reflection, too, arose early and modified original simplicity. But what is characteristic of the whole process is the fact that it went on continuously without breaks or sudden bounds. Nowhere in ancient religion, as far as we can trace it, did a powerful religious personality strike in with a radical transformation, with a direct rejection of old ideas and dogmatic accentuation of new ones. The result of this quiet growth was an exceedingly heterogeneous organism, in which remains of ancient, highly primitive customs and ideas were retained along with other elements of a far more advanced character.