 Contemporary philosophers sometimes discuss external world skepticism in terms of a paradox: one thinker finds herself torn between the strength of skeptical arguments and her ordinary convictions. For example, she thinks that this is her hand. But she concedes that the skeptical hypothesis that a mad scientist might have set things up so that she has such perceptions and thoughts (the so-called brain in a vat scenario) is hard to refute. This way of framing discussions of skepticism is foreign to antiquity. In antiquity, skeptics and their opponents are different thinkers, each of them with one set of intuitions, arguing against each other. It is also foreign to ancient skepticism insofar as it inherits the early modern idea that some greatly powerful agent sets things up, and in a sense creates the thinker’s faculties and the world as it appears to them.