Accurate and just reasoning is the only catholic remedy, fitted for all persons and all dispositions; and is alone able to subvert that abstruse philosophy and metaphysical jargon, which, being mixed up with popular superstition, renders it in a manner impenetrable to careless reasoners, and gives it the air of science and wisdom.

The difference between a man who is led by opinion or emotion and one who is led by reason. The former, whether he will or not, performs things of which he is entirely ignorant; the latter is subordinate to no one, and only does those things which he knows to be of primary importance in his life, and which on that account he desires the most; and therefore I call the former a slave, but the latter free.

Nothing is more favorable to the rise of politeness and learning, than a number of neighboring and independent states, connected together by commerce and policy.

..when, in my philosophical disquisitions, I deny a providence and a future state, I undermine not the foundations of society, but advance principles, which they themselves, upon their own topics, if they argue consistently, must allow to be solid and satisfactory.

Vanity is so closely allied to virtue, and to love the fame of laudable actions approaches so near the love of laudable actions for their own sake, that these passions are more capable of mixture than any other kinds of affection; and it is almost impossible to have the latter without some degree of the former.

Moving from an objective statement of fact to a subjective statement of value does not work, because it leaves open questions that have not been answered.

.. that a rule, which, in speculation, may seem the most advantageous to society, may yet be found, in practice, totally pernicious and destructive.