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: 1958

"Consciousness is like a bottomless lake in which ideas are suspended at different depths."

— Peirce, Charles Sanders (1839-1914)

Date: 1976

"They [Marsall McLuhan's ideas] are Turkish baths of the mind."

— Bell, Daniel (1919-2011)

Date: 1979

" But they can be sent along the usual channels […] until at some critical point, a "mental faucet" is closed, preventing them from actually being carried out."

— Hofstadter, Douglas (b. 1945)

Date: 1981

"When we introspect we do not perceive 'concepts' flowing through our minds as such. Stop the stream of thought when or where we will, what we catch are words, images, sensations, feelings."

— Putnam, Hilary (b. 1926)

Date: 1983

"Hume's account of mental happenings is geographical in the broadest sense, a description of human economy and ecology, not just a record of topography and a positioning of land masses but a marking of the tidal movements and trade routes of the mind as it negotiates for ease and stability."

— Richetti, John (b. 1938)

Date: 1989

"Indeed, it is this very push and pull that produces lieux de mémoire--moments of history torn away from the movement of history, then returned; no longer quite life, not yet death, like shells on the shore when the sea of living memory has receded."

— Nora, Pierre (b. 1931)

Date: November 22, 1990

"I do not feel alive, except insofar as a stream of feeling -- perceiving, imagining, remembering, reflecting, revising, recategorizing runs through me."

— Sacks, Oliver (b. 1933)

Date: 1999

"On its own this trigger, as we can see from the earlier definition, is not going to generate consciousness. Imagine a candyfloss machine with a stick in the centre that then gathers more and more candyfloss as time goes on. Think of the epicentre as the stick in the centre, the burgeoning candy...

— Greenfield, Susan (b. 1950)

Date: 1999

"Perhaps the consciousness of dreaming is the almost random formation of little groups forming in different configurations like pebbles thrown very gently into the water. One can imagine the gentle ripples easily being displaced by the next pebble as it hits the water."

— Greenfield, Susan (b. 1950)