 This 300 line fragment discusses self-perception, and argues that all birds, reptiles, and mammals from the moment of birth perceive themselves continuously and that self-perception is both the primary and the most basic faculty of animals.The argument draws heavily on a Stoic concept known as self-ownership or oikeiôsis () which was based on the view that all animals behave in a self-preserving way and are not just aware of themselves, but are aware of themselves in relation of other animals.Hierocles's argument about self-perception was part of the groundwork for an entire theory of ethics.