This chapter explores the Histories’ interest in human nature on the battlefield in terms of valour. It reviews instances in which the historical actors – including Pixodarus, Xerxes, and Themistocles – foreground the strategic importance of "surpassing nature." This is a motif that places the speakers in a network of sophistic and later, Platonic, theories on man’s desire to outstrip his own nature. At stake is a philosophy of "superior nature" that is strongly undercut by the complexity of the action on the battlefield.

The study of nature as an object of scientific interest matured through the investigations of Presocratic philosophers on the observable world. Herodotus is in dialogue with those expanding its domain into the spheres of natural science and the human. Physis embraces the interior and exterior regularities of subjects as diverse as landmasses, rivers, seas, elements, animals, and men. Unique to Herodotus, however, is the use of nature as a category of historical explanation; it is a standard of measurement that permits historical inference.

The paper examines the origins of the distinction between physis, “nature,” and nomos, “norm,” and the uses made of it during the period of the Sophists. The two terms did not originally lend themselves to being contrasted, but the contrast becomes natural in light of two mid-fifth-century developments: a growing interest in the different customs of different societies and a proliferation of accounts of the origins of human civilization. While the contrast is employed by others, such as Herodotus and the medical writers, it is the Sophists themselves, above all, who exploit it for sociological and philosophical purposes. Some, such as Protagoras, see nomos as building on physis – that is, on tendencies in human nature; others see an opposition between the two, and suggest that we would be better off ignoring nomos and attending to what our natures dictate. The contrast is also applied to religion, which some Sophists treat as nomos.