Human Nature is the only science of man; and yet has been hitherto the most neglected.

Anything that is conceivable is possible.

When the coherence of the parts of a stone, or even that composition of parts which renders it extended; when these familiar objects, I say, are so inexplicable, and contain circumstances so repugnant and contradictory; with what assurance can we decide concerning the origin of worlds, or trace their history from eternity to eternity?

Apart from the representational content of an idea there is another component: its force and vivacity, its impetus.

The ages of greatest public spirit are not always eminent for private virtue.

The gazing populace receive greedily, without examination, whatever soothes superstition and promotes wonder.

Liberty of thinking, and of expressing our thoughts, is always fatal to priestly power, and to those pious frauds on which it is commonly founded.