A CAUSE is an object precedent and contiguous to another, and so united with it that the idea of the one determines the mind to form the idea of the other, and the impression of the one to form a more lively idea of the other.

The rules of morality are not the conclusion of our reason.

... if you insist that the inference is made by a chain of reasoning, I desire you to produce that reasoning. The connection between the two is not intuitive. There is required a medium, which may enable the mind to draw such an inference, if indeed it be drawn by reasoning and argument. What that medium is, I must confess, passes my comprehension; and it is incumbent on those to produce it, who assert that it really exists, and is the origin of all our conclusions concerning matter of fact.

There is a very remarkable inclination in human nature to bestow on external objects the same emotions which it observes in itself, and to find every where those ideas which are most present to it.

Nothing can be more real, or concern us more, than our own sentiments of pleasure and uneasiness; and if these be favourable to virtue and unfavourable to vice, no more can be requisite to the regulation of our conduct and behavior.

From causes which appear similar, we expect similar effects. This is the sum total of all our experimental conclusions.

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.