Patriotism is the last refuge of the scoundrel.

Knowledge is praised and desired by multitudes whom her charms could never rouse from the couch of sloth; whom the faintest invitation of pleasure draws away from their studies; to whom any other method of wearing the day is more eligible than the use of books, and who are more easily engaged by any conversation than such as may rectify their notions or enlarge their comprehension.

Ignorance, when it is voluntary, is criminal.

Perhaps man is the only being that can properly be called idle.

Every cold empirick, when his heart is expanded by a successful experiment, swells into a theorist.

Human experience, which is constantly contradicting theory, is the great test of truth. A system, built upon the discoveries of a great many minds, is always of more strength, than what is produced by the mere workings of any one mind, which, of itself, can do very little. There is not so poor a book in the world that would not be a prodigious effort were it wrought out entirely by a single mind, without the aid of prior investigators.

Health is so necessary to all the duties, as well as pleasures of life, that the crime of squandering it is equal to the folly.