 Although it is occasionally suggested that a concern with self-consciousness is a peculiarly modern phenomenon, originating with Descartes (Brinkmann 2005), it is in fact the topic of lively ancient and medieval debates, many of which prefigure early modern and contemporary concerns (Sorabji 2006). Aristotle, for example, claims that a person must, while perceiving any thing, also perceive their own existence (De Sensu 7.448a), a claim suggestive of the view that consciousness entails self-consciousness. Furthermore, according to Aristotle, since the intellect takes on the form of that which is thought (Kahn 1992), it “is thinkable just as the thought-objects are” (De Anima 3.4.430), an assertion that was interpreted by Aristotle’s medieval commentators as the view that self-awareness depends on an awareness of extra-mental things (Cory 2014: ch. 1; Owens 1988).