Introspection, psychology of

1. The classical conception

The term ‘introspection’ comes from the Latin ‘spicere’ (to look) and ‘intra’ (within). In ordinary English, it means ‘the observation of one’s own mental states or processes’. As we shall see in §3, whether introspection truly constitutes a form of observation is a matter of dispute. However, it is generally agreed that introspection involves awareness of certain aspects of one’s mind, specifically, an awareness that involves a ‘higher-order’ belief or representation that one is in some ‘lower-order’ mental state. (A thought about cats is a ‘first-order’ mental state, whereas a belief that one has a thought about cats is ‘second-order’.)

The first important treatment of introspection is that of Descartes (1641), who held that there is nothing to the mind but what is in consciousness and available to introspection (see Consciousness §7; Introspection, epistemology of). Introspective awareness of our mental states and processes might be thought to be the result of a separate higher-order process trained on lower-order states and processes. However, for Descartes, the connection is much closer than that: mental states and processes are, on his view, ‘self-intimating’. It is sufficient simply for a mental state or process to be ‘within us’ for us to be aware of it. Indeed, Descartes held that the beliefs that result from introspection are infallible. As long as we consider our mental states only as they are ‘in themselves’, they cannot be false.