Notion of natural enemy in Greek historiography on fifth century B.C.

According to Herodotus, true enemies by nature are the same Greek people who carry strong historic ancestral disputes. For Thucydides, the natural enmity is represented in the ethnic hostility of the Sicilian colonies towards its metropolis Athens. The notion of natural enmity has multiple meanings and uses, but very different from that which flourished during the Hellenistic era.