I make this chief distinction between religion and superstition, that the latter is founded on ignorance, the former on knowledge.

If we love something similar to ourselves, we endeavor, as far as we can, to bring it about that it should love us in return.

I can control my passions and emotions if I can understand their nature

Big fish eat small fish with as much right as they have power.

The idea, which constitutes the actual being of the human mind, is not simple, but compounded of a great number of ideas.

No to laugh, not to lament, not to detest, but to understand.

Of all the things that are beyond my power, I value nothing more highly than to be allowed the honor of entering into bonds of friendship with people who sincerely love truth. For, of things beyond our power, I believe there is nothing in the world which we can love with tranquility except such men.