Date: 1900

"But thought that strives to reunite / In polished facets of the mind / The broken colours of the light / Baffled in mists of human kind."

— Money-Coutts, Francis Burdett Thomas, 5th Lord Latimer (1852-1923)

Date: 1949

"Self-consciousness, if the word is to be used at all, must not be described on the hallowed para-optical model, as a torch that illuminates itself by beams of its own light reflected from a mirror in its own insides."

— Ryle, Gilbert (1900-1976)

Date: 1949

"Mental states and processes are (or are normally) conscious states and processes, and the consciousness which irradiates them can engender no illusions and leaves the door open for no doubts."

— Ryle, Gilbert (1900-1976)

Date: 1949

"A person's present thinkings, feelings and willings, his perceivings, rememberings and imaginings are intrinsically 'phospherescent'; their existence and their nature are inevitably betrayed to their owner."

— Ryle, Gilbert (1900-1976)

Date: 1949

"Rather, to relapse perforce into simile, it is supposed that mental processes are phosphorescent, like tropical sea-water, which makes itself visible by the light which it itself emits."

— Ryle, Gilbert (1900-1976)

Date: 1999

"As the brain gets more complex in the womb, then, like a dimmer switch, consciousness gradually grows and burgeons until, of course, in adulthood it reaches its particular pinnacles or depths."

— Greenfield, Susan (b. 1950)