Date: 1960

"Physical things generally, however remote, become known to us only through the effects which they help induce at our sensory surfaces."

— Quine, W. V. O. (1908-2000)

Date: August, 1963

"But when you have seen vicious mobs lynch your mothers and fathers at will and drown your sisters and brothers at whim; when you have seen hate-filled policemen curse, kick, brutalize, and even kill your black brothers and sisters with impunity; when you see the vast majority of your twenty mill...

— King, Martin Luther [Michael] (1929-1968)

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

"If one must use metaphorical language, then let the metaphor be this: the mind and the world jointly make up the mind and the world. (Or, to make the metaphor even more Hegelian, the Universe makes up the Universe--with minds--collectively--playing a special role in the making up.)"

— Putnam, Hilary (b. 1926)