Date: 1686, 1689, 1697

"Learning ought to be infus'd into the Scholar like spirits into a Bottle, by little and little, for whosoever attempts to pour in all at once, may in all likelihood spill a great part, and in a great measure fill the Vessel with Wind and Air."

— Nourse, Timothy (c.1636–1699)

Date: 1711

"These Spirits rais'd from Choler to the Brain, / Like those extracted from the basest Grain, / Impure and crude, produce unnatural Heat, / And an ignoble Flame of Life create."

— Blackmore, Sir Richard (1654-1729)

Date: January 1739

"The vividness of the first conception diffuses itself along the relations, and is convey'd, as by so many pipes or canals, to every idea that has any communication with the primary one."

— Hume, David (1711-1776)

Date: January 1739

"The attention is on the stretch; the posture of the mind is uneasy; and the spirits being diverted from their natural course, are not governed in their movements by the same laws, at least not to the same degree, as when they flow in their usual channel."

— Hume, David (1711-1776)

Date: March 11, 2011

"The huge submerged bulk of the mental iceberg, with its stores of memory and acquired skills that have become automatic, like language, driving and etiquette, supplies people with the raw materials on which they can exercise their reason and decide what to think and what to do."

— Nagel, Thomas (b. 1937)