As men's habits of mind differ, so that some more readily embrace one form of faith, some another, for what moves one to pray may move another to scoff, I conclude ... that everyone should be free to choose for himself the foundations of his creed, and that faith should be judged only by its fruits.

One and the same thing can at the same time be good, bad, and indifferent, e.g., music is good to the melancholy, bad to those who mourn, and neither good nor bad to the deaf.

In the mind there is no absolute or free will; but the mind is determined to wish this or that by a cause, which has also been determined by another cause, and this last by another cause, and so on to infinity.

The things which ... are esteemed as the greatest good of all ... can be reduced to these three headings, to wit : Riches, Fame, and Pleasure. With these three the mind is so engrossed that it cannot scarcely think of any other good.

The proper study of a wise man is not how to die but how to live.

Freedom is absolutely necessary for the progress in science and the liberal arts.

In the state of nature, wrong-doing is impossible ; or, if anyone does wrong, it is to himself, not to another.