Years should not be devoted to the acquisition of dead languages or to the study of history which, for the most part, is a detailed account of things that never occurred. It is useless to fill the individual with dates of great battles, with the births and deaths of kings. They should be taught the philosophy of history, the growth of nations, of philosophies, theories, and, above all, of the sciences.

But honest men do not pretend to know; they are candid and sincere; they love the truth; they admit their ignorance, and they say, We do not know.

Laughing has always been considered by theologians as a crime.

My principal objections to orthodox religion are two: slavery here and hell hereafter.

You cannot be so poor that you cannot help somebody.

Memory is the miser of the mind; forgetfulness the spendthrift.

My heart was filled with gratitude, with thankfulness, and went out in love to all the heroes, the thinkers who gave their lives for the liberty of hand and brain... to all the wise, the good, the brave of every land, whose thoughts and deeds have given freedom to the sons of men. And then I vowed to grasp the torch that they had held, and hold it high, that light might conquer darkness still.