Those who fear the facts will forever try to discredit the fact-finders.

In general, children, like men, and men, like children, prefer entertainment to education.

If you disturb the colors of the rainbow, the rainbow is no longer beautiful.

All things must be examined, debated, investigated without exception and without regard for anyone's feelings.

Does not vanity itself cease to be blamable, is it not even ennobled, when it is directed to laudable objects, when it confines itself to prompting us to great and generous actions?

A thing is not proved just because no one has ever questioned it. What has never been gone into impartially has never been properly gone into. Hence scepticism is the first step toward truth. It must be applied generally, because it is the touchstone.

A thing is not proved because no one has ever questioned it... Skepticism is the first step toward truth.