Courage, of all national qualities, is the most precarious; because it is exerted only at intervals, and by a few in every nation; whereas industry, knowledge, civility, may be of constant and universal use, and for several ages, may become habitual to the whole people.

The bigotry of theologians is a malady which seems almost incurable.

Examine the religious principles which have, in fact, prevailed in the world. You will scarcely be persuaded that they are other than sick men's dreams.

Nothing is demonstrable, unless the contrary implies a contradiction. Nothing, that is distinctly conceivable, implies a contradiction. Whatever we conceive as existent, we can also conceive as non-existent. There is no being, therefore, whose non-existence implies a contradiction. Consequently there is no being, whose existence is demonstrable.

From the apparent usefulness of the social virtues, it has readily been inferred by sceptics, both ancient and modern, that all moral distinctions arise from education, and were, at first, invented, and afterwards encouraged ... in order to render men tractable, and subdue their natural ferocity and selfishness, which incapacitated them for society.

Even after the observation of the frequent conjunction of objects, we have no reason to draw any inference concerning any object beyond those of which we have had experience.

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