This chapter surveys the evidence for the sophistic debate on relativism as evident in the fragments of the sophists, including comic and tragic poets. A widespread interpretation of the Histories claims that Herodotus supports nomos without qualification. By contrast, this chapter argues that this claim fails to capture the complexity of Herodotus’ engagement with those figures who use nomos as a rhetorical ploy to justify what is contrary to popular ethics. Similarly, Presocratic thinkers were working through the challenges presented by those who identified nomos as only a relative set of values as opposed to an objective norm to be followed. The Histories’ exploration of the problem of relating custom and law to justice takes place in the context of the rise and expansion of Persian imperialism. Further, it implicates the despot in a relativizing of justice and constitutes a key explanatory paradigm in the Persian attack against the Greek mainland in the Greco-Persian Wars.