Our observation of nature must be diligent, our reflection profound, and our experiments exact. We rarely see these three means combined; and for this reason, creative geniuses are not common.
It is not human nature we should accuse but the despicable conventions that pervert it.
It is said that desire is a product of the will, but the converse is in fact true: will is a product of desire.
In order to shake a hypothesis, it is sometimes not necessary to do anything more than push it as far as it will go.
Justice is the first virtue of those who command, and stops the complaints of those who obey.
All abstract sciences are nothing but the study of relations between signs.
Morals are in all countries the result of legislation and government; they are not African or Asian or European: they are good or bad.
My ideas are my whores.
No man has received from nature the right to command his fellow human beings.
One declaims endlessly against the passions; one imputes all of man's suffering to them. One forgets that they are also the source of all his pleasures.
Only passions, great passions can elevate the soul to great things.
Patriotism is an ephemeral motive that scarcely ever outlasts the particular threat to society that aroused it.
People praise virtue, but they hate it, they run away from it. It freezes you to death, and in this world you've got to keep your feet warm.
Only a very bad theologian would confuse the certainty that follows revelation with the truths that are revealed. They are entirely different things.
If you want me to believe in God, you must make me touch him.