You can never plan the future by the past.

Man acts from adequate motives relative to his interest, and not on metaphysical speculations.

I take toleration to be a part of religion. I do not know which I would sacrifice; I would keep them both: it is not necessary that I should sacrifice either.

As mankind becomes more enlightened to know their real interests, they will esteem the value of agriculture; they will find it in their natural--their destined occupation.

I do not hesitate to say that the road to eminence and power, from an obscure condition, ought not to be made too easy, nor a thing too much of course. If rare merit be the rarest of all things, it ought to pass through some sort of probation. The temple of honor ought to be seated on an eminence. If it be open through virtue, let it be remembered, too, that virtue is never tried but by some difficulty and some struggle.

It is from this absolute indifference and tranquillity of the mind, that mathematical speculations derive some of the most considerable advantages; because there is nothing to interest the imagination; because the judgment sits free and unbiased to examine the point. All proportions, every arrangement of quantity, is alike to the understanding, because the same truths result to it from all; from greater from lesser, from equality and inequality.

Taste and elegance, though they are reckoned only among the smaller and secondary morals, yet are of no mean importance in the regulations of life. A moral taste is not of force to turn vice into virtue; but it recommends virtue with something like the blandishments of pleasure, and it infinitely abates the evils of vice.