While, however, we can discern in Herodotus the rise of an historic sense, we must not blind ourselves to the large amount of instances where he receives supernatural influences as part of the ordinary forces of life. Compared to Thucydides, who succeeded him in the development of history, he appears almost like a mediæval writer matched with a modern rationalist. For, contemporary though they were, between these two authors there is an infinite chasm of thought. The essential difference of their methods may be best illustrated from those passages where they treat of the same subject. The execution of the Spartan heralds, Nicolaos and Aneristos, during the Peloponnesian War is regarded by Herodotus as one of the most supernatural instances of the workings of nemesis and the wrath of an outraged hero; while the lengthened siege and ultimate fall of Troy was brought about by the avenging hand of God desiring to manifest unto men the mighty penalties which always follow upon mighty sins. But Thucydides either sees not, or desires not to see, in either of these events the finger of Providence, or the punishment of wicked doers. The death of the heralds is merely an Athenian retaliation for similar outrages committed by the opposite side; the long agony of the ten years’ siege is due merely to the want of a good commissariat in the Greek army; while the fall of the city is the result of a united military attack consequent on a good supply of provisions. Now, it is to be observed that in this latter passage, as well as elsewhere, Thucydides is in no sense of the word a sceptic as regards his attitude towards the truth of these ancient legends. Agamemnon and Atreus, Theseus and Eurystheus, even Minos, about whom Herodotus has some doubts, are to him as real personages as Alcibiades or Gylippus. The points in his historical criticism of the past are, first, his rejection of all extra-natural interference, and, secondly, the attributing to these ancient heroes the motives and modes of thought of his own day. The present was to him the key to the explanation of the past, as it was to the prediction of the future. Now, as regards his attitude towards the supernatural he is at one with modern science. We too know that, just as the primeval coal-beds reveal to us the traces of rain-drops and other atmospheric phenomena similar to those of our own day, so, in estimating the history of the past, the introduction of no force must be allowed whose workings we cannot observe among the phenomena around us. To lay down canons of ultra-historical credibility for the explanation of events which happen to have preceded us by a few thousand years, is as thoroughly unscientific as it is to intermingle preternatural in geological theories. Whatever the canons of art may be, no difficulty in history is so great as to warrant the introduction of a spirit of spirit _θεὸς ἀπὸ μηχανῆς_, in the sense of a violation of the laws of nature.