Men ought to know that from nothing else but the brain come joins, delights, laughter and sports, and sorrows, griefs, despondency, and lamentations. And by this, in a special manner, we acquire wisdom and knowledge, and see and hera and known what are foul and what are faire, what are bad and what are good, what are sweet and what are unsavory... And by the same organ we become mad and delirious, and feras and terros assail us... All these things we endure from the brain when it is not healthy... In these ways I am of the opinion that the brain exercises the greatest power in the man.
Hippocrates

The highest possible stage in moral culture is when we recognize that we ought to control our thoughts.
Charles Darwin

William James used to preach the "will to believe". For my part, I should wish to preach the "will to doubt"...
What is wanted is not the will to believe, but the wish to find out, which is the exact opposite.
Bertrand Russel

One definition of man is "an intelligence served by organs."
Ralph Waldo Emerson

The test of a first-rate intelligence is the ability to hold two opposed ideas in the mind at the same time, and still retain the ability to function.
F. Scott Fitzgerald

The human head is bigger than the globe. It conceives itself as containing more. It can think and rethink itself and ourselves from any desired point outside the gravitational pull of the earth. It starts by writing one thing and later reads itself as something else. The human head is monstrous.
Günther Grass

Everything tends to make us believe that there exists a certain point of the mind at which life and death, the real and the imagined, past and future, the communicable and the incommunicable, high and low, cease to be perceived as contradictions.
André Breton

It's a pleasure to share one's memories. Everything remembered is dear, endearing, touching, precious. At least the past is safe-though we didn't know it at the time. We know it now. Because it's in the past; because we have survived.
Susan Sontag

In order to be able to set a limit to thought, we should have to find both sides of the limit thinkable (i.e. we should have to be able to think what cannot be thought).
Ludwig Wittgenstein

To reflect is to disturb one's thoughts.
Jean Rostand (1894-1977), French biologist, writer.

Madness is something rare in individuals-but in groups, parties, peoples, ages it is the rule.
Friedrich Nietzsche (1844-1900), German philosopher.

To be good, according to the vulgar standard of goodness, is obviously quite easy. It merely requires a certain amount of sordid terror, a certain lack of imaginative thought, and a certain low passion for middle-class respectability.
Oscar Wilde (1854-1900)

He who undervalues himself is justly undervalued by others.
William Hazlitt (1778-1830), English essayist.

One may understand the cosmos, but never the ego; the self is more distant than any star. G. K. Chesterton (1874-1936), British author.