The end of all moral speculations is to teach us our duty; and, by proper representations of the deformity of vice and beauty of virtue, beget correspondent habits, and engage us to avoid the one, and embrace the other.

To invent without scruple a new principle to every new phenomenon, instead of adapting it to the old; to overload our hypothesis with a variety of this kind, are certain proofs that none of these principles is the just one, and that we only desire, by a number of falsehoods, to cover our ignorance of the truth.

Mankind are so much the same, in all times and places, that history informs us of nothing new or strange in this particular. Its chief use is only to discover the constant and universal principles of human nature.

He sees such a desperate rapaciousness prevail; such a disregard to equity, such contempt of order, such stupid blindness to future consequences, as must immediately have the most tragical conclusion, and most terminate in destruction to the greater number, and in a total dissolution of society to the rest.

If refined sense, and exalted sense, be not so useful as common sense, their rarity, their novelty, and the nobleness of their objects, make some compensation, and render them the admiration of mankind.

[Rousseau] has not had the precaution to throw any veil over his sentiments; and as he scorns to dissemble his contempt of established opinions, he could not wonder that all the zealots were in arms against him.

All knowledge resolves itself into probability. ... In every judgment, which we can form concerning probability, as well as concerning knowledge, we ought always to correct the first judgment deriv'd from the nature of the object, by another judgment, deriv'd from the nature of the understanding.