All men are liable to error; and most men are, in many points, by passion or interest, under temptation to it.

Religion, which should most distinguish us from the beasts, and ought most particularly elevate us, as rational creatures, above brutes, is that wherein men often appear most irrational, and more senseless than beasts.

It is one thing to show a man that he is in error, and another to put him in possession of the truth.

False and doubtful positions, relied upon as unquestionable maxims, keep those who build on them in the dark from truth. Such are usually the prejudices imbibed from education, party, reverence, fashion, interest, et cetera.

He that knows anything, knows this, in the first place, that he need not seek long for instances of his ignorance.

I doubt not, but from self-evident Propositions, by necessary Consequences, as incontestable as those in Mathematics, the measures of right and wrong might be made out.

He that uses his words loosely and unsteadily will either not be minded or not understood.

Since sounds have no natural connection with our ideas ... the doubtfulness and uncertainty of their signification ... has its cause more in the ideas they stand for than in any incapacity there is in one sound more than another to signify any idea.

The boundaries of the species, whereby men sort them, are made by men.

Preference of vice to virtue, a manifest wrong judgment.