Extrospection is a process of cognition directed outward — a process of apprehending some existent(s) of the external world. Introspection is a process of cognition directed inward — a process of apprehending one’s own psychological actions in regard to some existent(s) of the external world, such actions as thinking, feeling, reminiscing, etc. It is only in relation to the external world that the various actions of a consciousness can be experienced, grasped, defined or communicated.
A major source of men’s earned guilt in regard to philosophy — as well as in regard to their own minds and lives — is failure of introspection. Specifically, it is the failure to identify the nature and causes of their emotions.
An emotion as such tells you nothing about reality, beyond the fact that something makes you feel something. Without a ruthlessly honest commitment to introspection — to the conceptual identification of your inner states — you will not discover what you feel, what arouses the feeling, and whether your feeling is an appropriate response to the facts of reality, or a mistaken response, or a vicious illusion produced by years of self-deception. The men who scorn or dread introspection take their inner states for granted, as an irreducible and irresistible primary, and let their emotions determine their actions. This means that they choose to act without knowing the context (reality), the causes (motives), and the consequences (goals) of their actions.
The field of extrospection is based on two cardinal questions: “What do I know?” and “How do I know it?” In the field of introspection, the two guiding questions are: “What do I feel?” and “Why do I feel it?”
In regard to one’s own feelings, only a rigorously conscientious habit of introspection can enable one to be certain of the nature and causes of one’s emotional responses.
The formation of introspective concepts follows the same principles as the formation of extrospective concepts. A concept pertaining to consciousness is a mental integration of two or more instances of a psychological process possessing the same distinguishing characteristics, with the particular contents and the measurements of the action’s intensity omitted—on the principle that these omitted measurements must exist in some quantity, but may exist in any quantity (i.e., a given psychological process must possess some content and some degree of intensity, but may possess any content or degree of the appropriate category).