A good marriage (if any there be) refuses the conditions of love and endeavors to present those of amity.

Laws gain their authority from actual possession and custom: it is perilous to go back to their origins; laws, like our rivers, get greater and nobler as they roll along: follow them back upstream to their sources and all you find is a tiny spring, hardly recognizable; as time goes by it swells with pride and grows in strength.

To philosophize is to doubt.

To make judgements about great and lofty things, a soul of the same stature is needed; otherwise we ascribe to them that vice which is our own.

The world is but a school of inquisition; it is not who shall enter the ring, but who shall run the best courses.

I put forward formless and unresolved notions, as do those who publish doubtful questions to debate in the schools, not to establish the truth but to seek it.

Virtue shuns ease as a companion. It demands a rough and thorny path.