While the simplistic thesis of Greek progress from mythos to logos in the form stated by Wilhelm Nestle is rightly rejected, some aspects of the emerging new consensus are open to challenge. ‘Mythos’ corresponds in important ways to modern ‘myth’ and Greek logos, with which it is contrasted, stands at the beginning of an unbroken tradition of Western rationalism. The semantic history of the terms is freshly analyzed, with particular attention to the contribution of pre-Socratic philosophers, Herodotos and Sophists, but looking forward also to Hellenistic and Imperial writers. The ‘invention of mythology’ is dated to the middle of the fifth century, not the end. Plato's complicated stand on the issue is interpreted as a reaction to Sophistic views.