To begin with, the attempt to give a natural explanation of prodigies is not in itself without interest. The mantic art, _i.e._ the ability to predict the future by signs from the gods or direct divine inspiration, was throughout antiquity considered one of the surest proofs of the existence of the gods. Now, it by no means follows that a person who was not impressed by a deformed ram’s head would deny, _e.g._, the ability of the Delphic Oracle to predict the future, especially not so when the person in question was a naturalist. But that there was at this time a general tendency to reject the art of divination is evident from the fact that Herodotus as well as Sophocles, both of them contemporaries of Pericles and Anaxagoras, expressly contend against attempts in that direction, and, be it remarked, as if the theory they attack was commonly held. Sophocles is in this connexion so far the more interesting of the two, as, on one hand, he criticises private divination but defends the Delphic oracle vigorously, while he, on the other hand, identifies denial of the oracle with denial of the gods. And he does this in such a way as to make it evident that he has a definite object in mind. That in this polemic he may have been aiming precisely at Anaxagoras is indicated by the fact that Diopeithes, who carried the resolution concerning the accusation of the philosopher, was a soothsayer by profession. The strongest evidence as to the free-thinking of the Periclean age is, however, to be met with in the historical writing of Thucydides. In his work on the Peloponnesian War, Thucydides completely eliminated the supernatural element; not only did he throughout ignore omens and divinations, except in so far as they played a part as a psychological factor, but he also completely omitted any reference to the gods in his narrative. Such a procedure was at this time unprecedented, and contrasts sharply with that of his immediate forerunner Herodotus, who constantly lays stress on the intervention of the gods. That is hardly conceivable except in a man who had altogether emancipated himself from the religious views of his time. Now, Thucydides is not only a fellow-countryman and younger contemporary of Pericles, but he also sees in Pericles his ideal not only as a politician but evidently also as a man. Hence, when everything is considered, it is not improbable that Pericles and his friends went to all lengths in their criticism of popular belief, although, of course, it remains impossible to state anything definite as to particular persons’ individual views. Curiously enough, even in antiquity this connexion was observed; in a biography of Thucydides it is said that he was a disciple of Anaxagoras and _accordingly_ was also considered something of an atheist.