Imagination is the activity of generating or evoking novel situations, images, ideas or other qualia in the mind.
There is a lengthy tradition in philosophy, religion, psychology, and cognitive science about what constitutes a mind and what are its distinguishing properties.
One open question regarding the nature of the mind is the mind–body problem, which investigates the relation of the mind to the physical brain and nervous system.
Important philosophers of mind include Plato, Descartes, Leibniz, Locke, Berkeley, Hume, Kant, Hegel, Schopenhauer, Searle, Dennett, Fodor, Nagel, and Chalmers.
Psychologists such as Freud and James, and computer scientists such as Turing and Putnam developed influential theories about the nature of the mind.
Although memory has traditionally been a persistent theme in philosophy, the late nineteenth and early twentieth centuries also saw the study of memory emerge as a subject of inquiry within the paradigms of cognitive psychology.