"If we would satisfy ourselves, therefore, concerning the nature of that evidence, which assures us of matters of fact, we must enquire how we arrive at the knowledge of cause and effect."

"The imagination is a great source of error."

"In order, therefore, to impose a due restraint on the female sex, we must attach a peculiar degree of shame to their infidelity, above what arises merely from its injustice, and must bestow proportion…"

"To be a philosophical sceptic is, in a man of letters, the first and most essential step towards being a true philosopher."

"What a peculiar privilege has this little agitation of the brain which we call thought!"