Selfishness is the root and source of all natural and moral evils.

Habit is either the best of servants or the worst of masters.

These two rules make the best system: first, have something to say; second, say it.

Insanity destroys reason, but not wit.

Just definitions either prevent or put an end to disputes.

Steady, patient, persevering thinking will generally surmount every obstacle in search of truth.

Any fact is better established by two or three good testimonies than by a thousand arguments.