It is easier to deceive yourself, and to do so unperceived, than to deceive another.

Idiots and lunatics see only their own wit.

The passions of youth are not more dangerous to health than is the lukewarmness of old age.

Considering how little the beginning or the ceasing to love is in our own power, it is foolish and unreasonable for the lover or his mistress to complain of one another's inconstancy.

Gratitude is like the good faith of traders: it maintains commerce, and we often pay, not because it is just to discharge our debts, but that we may more readily find people to trust us.

Spiritual health is no more stable than bodily; and though we may seem unaffected by the passions we are just as liable to be carried away by them as to fall ill when in good health.

Luxury and excessive refinement are sure forerunners of the decadence of states, because when all individuals seek their own interests they neglect the public weal.