It's not those who write the laws that have the greatest impact on society. It's those who write the songs.

Fear not, provided you fear; but if you fear not, then fear.

If you want to be a real seeker of truth, you need to, at least once in your lifetime, doubt in, as much as it's possible, in everything.

Piety is different from superstition. To carry piety to the extent of superstition is to destroy it. The heretics reproach us with this superstitious submission. It is doing what they reproach us with.

By a peculiar prerogative, not only each individual is making daily advances in the sciences, and may make advances in morality (which is the science, by way of eminence, of living well and being happy), but all mankind together is making a continual progress in proportion as the universe grows older. So that the whole human race, during the course of so many ages, may be considered as one man who never ceases to live and learn.

All who say the same things do not possess them in the same manner; and hence the incomparable author of the Art of Conversation pauses with so much care to make it understood that we must not judge of the capacity of a man by the excellence of a happy remark that we heard him make. Let us penetrate, says he, the mind from which it proceeds. It will oftenest be seen that he will be made to disavow it on the spot, and will be drawn very far from this better thought in which he does not believe, to plunge himself into another, quite base and ridiculous.

Lust is the source of all our actions, and humanity.