Reason

"Contrariwise," continued Tweedledee, "if it was so, it might be, and if it were so, it would be; but as it isn't, it ain't. That's logic!"

-- Lewis Carroll, Alice in Wonderland

Viewed from the summit of reason, all life looks like a malignant disease and the world like a madhouse.

-- Johann Wolfgang von Goethe

The heart has its reasons of which reason knows nothing.

-- Blaise Pascal, Pens&eactue;es, trans. A.J. Krailsheimer

We know the truth, not only by the reason, but also by the heart.

-- Blaise Pascal, Thoughts, Chap. x. 1., Translated by O. W. Wight

Man is a rational animal who always loses his temper when he is called upon to act in accordance with the dictates of reason.

-- Oscar Wilde