Everyone endeavors as much as possible to make others love what he loves, and to hate what he hates... This effort to make everyone approve what we love or hate is in truth ambition, and so we see that each person by nature desires that other persons should live according to his way of thinking.

Superstition, then, is engendered, preserved, and fostered by fear.

The greatest secret of monarchic rule...is to keep men deceived and to cloak in the specious name of religion the fear by which they must be checked, so that they will fight for slavery as they would for salvation, and will think it not shameful, but a most honorable achievement, to give their life and blood that one man may have a ground for boasting.

Freedom is absolutely necessary for the progress in science and the liberal arts.

He who hates anyone will endeavor to do him an injury, unless he fears that a greater injury will thereby accrue to himself; on the other hand, he who loves anyone will, by the same law, seek to benefit him.

Better that right counsels be known to enemies than that the evil secrets of tyrants should be concealed from the citizens. They who can treat secretly of the affairs of a nation have it absolutely under their authority; and as they plot against the enemy in time of war, so do they against the citizens in time of peace.

Only that thing is free which exists by the necessities of its own nature, and is determined in its actions by itself alone.