As priestcraft was always the enemy of knowledge, because priestcraft supports itself by keeping people in delusion and ignorance, it was consistent with its policy to make the acquisition of knowledge a real sin.

Infidelity does not consist in believing, or in disbelieving; it consists in professing to believe what he does not believe. It is impossible to calculate the moral mischief, if I may so express it, that mental lying has produced in society. When a man has so far corrupted and prostituted the chastity of his mind, as to subscribe his professional belief to things he does not believe, he has prepared himself for the commission of every other crime.

Some writers have so confounded society with government, as to leave little or no distinction between them; whereas they are not only different, but have different origins ... Society is in every state a blessing, but Government, even in its best state, is but a necessary evil; in its worst state, an intolerable one.

When I contemplate the natural dignity of man; when I feel (for Nature has not been kind enough to me to blunt my feelings) for the honor and happiness of its character, I become irritated at the attempt to govern mankind by force and fraud, as if they were all knaves and fools, and can scarcely avoid disgust at those who are thus imposed upon.

A man will pass better through the world with a thousand open errors upon his back than in being detected in one sly falsehood. When one is detected, a thousand are suspected.

To believe that God created a plurality of worlds, at least as numerous as what we call stars, renders the Christian faith at once little and ridiculous; and scatters it in the mind like feathers in the air.

Nothing but heaven is impregnable to vice.