Evil always turns up in this world through some genius or other.

How easy it is to tell tales!

If there were a reason for preferring the Christian religion to natural religion, it would be because the former offers us, on the nature of God and man, enlightenment that the latter lacks. Now, this is not at all the case; for Christianity, instead of clarifying, gives rise to an infinite multitude of obscurities and difficulties.

One must be oneself very little of a philosopher not to feel that the finest privilege of our reason consists in not believing in anything by the impulsion of a blind and mechanical instinct, and that it is to dishonour reason to put it in bonds as the Chaldeans did. Man is born to think for himself.

The following general definition of an animal: a system of different organic molecules that have combined with one another, under the impulsion of a sensation similar to an obtuse and muffled sense of touch given to them by the creator of matter as a whole, until each one of them has found the most suitable position for its shape and comfort.

There is only one duty; that is to be happy.

I picture the vast realm of the sciences as an immense landscape scattered with patches of dark and light. The goal towards which we must work is either to extend the boundaries of the patches of light, or to increase their number. One of these tasks falls to the creative genius; the other requires a sort of sagacity combined with perfectionism.