In a vain man, the smallest spark may kindle into the greatest flame, because the materials are always prepared for it.

It is more rational to suspect knavery and folly than to discount, at a stroke, everything that past experience has taught me about the way things actually work

Almost every one has a predominant inclination, to which his other desires and affections submit, and which governs him, though perhaps with some intervals, though the whole course of his life.

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.

... superstitions, which, being unable to defend themselves on fair ground, raise these intangling brambles to cover and protect their weakness. Chased from the open country, these robbers fly into the forest, and lie in wait to break in upon every unguarded avenue of the mind, and overwhelm it with religious fears and prejudices. ... The idea of God, as meaning an infinitely intelligent, wise and good Being, arises from reflecting on the operations of our own mind, and augmenting, without limit, those qualities of goodness and wisdom.

Be a philosopher but, amid all your philosophy be still a man.

How can we satisfy ourselves without going on in infinitum? And, after all, what satisfaction is there in that infinite progression? Let us remember the story of the Indian philosopher and his elephant. It was never more applicable than to the present subject. If the material world rests upon a similar ideal world, this ideal world must rest upon some other; and so on, without end. It were better, therefore, never to look beyond the present material world.