Religious wars are not caused by the fact that there is more than one religion, but by the spirit of intolerance... the spread of which can only be regarded as the total eclipse of human reason.
In bodies moved, the motion is received, increased, diminished, or lost, according to the relations of the quantity of matter and velocity; each diversity is uniformity, each change is constancy.
There is only one thing that can form a bond between men, and that is gratitude... we cannot give someone else greater power over us than we have ourselves.
Law in general is human reason, inasmuch as it governs all the inhabitants of the earth: the political and civil laws of each nation ought to be only the particular cases in which human reason is applied.
Although born in a prosperous realm, we did not believe that its boundaries should limit our knowledge, and that the lore of the East should alone enlighten us.
There are only two cases in which war is just: first, in order to resist the aggression of an enemy, and second, in order to help an ally who has been attacked.
When the legislative and executive powers are united in the same person, or in the same body of magistrates, there can be no liberty; because apprehensions may arise, lest the same monarch or senate should enact tyrannical laws, to execute them in a tyrannical manner.
Slavery, properly so called, is the establishment of a right which gives to one man such a power over another as renders him absolute master of his life and fortune.
They who assert that a blind fatality produced the various effects we behold in this world talk very absurdly; for can anything be more unreasonable than to pretend that a blind fatality could be productive of intelligent beings?
The law of nations is naturally founded on this principle, that different nations ought in time of peace to do one another all the good they can, and in time of war as little injury as possible, without prejudicing their real interests.
If I knew of something that could serve my nation but would ruin another, I would not propose it to my prince, for I am first a man and only then a Frenchman... because I am necessarily a man, and only accidentally am I French.
Thus the creation, which seems an arbitrary act, supposes laws as invariable as those of the fatality of the Atheists. It would be absurd to say that the Creator might govern the world without those rules, since without them it could not subsist.