“...never [enter] into dispute or argument with another. I never saw an instance of one of two disputants convincing the other by argument. I have seen many, on their getting warm, becoming rude, & shooting one another. ... When I hear another express an opinion which is not mine, I say to myself, he has a right to his opinion, as I to mine; why should I question it? His error does me no injury, and shall I become a Don Quixote, to bring all men by force of argument to one opinion? ... There are two classes of disputants most frequently to be met with among us. The first is of young students, just entered the threshold of science, with a first view of its outlines, not yet filled up with the details & modifications which a further progress would bring to their knoledge. The other consists of the ill-tempered & rude men in society, who have taken up a passion for politics. ... Consider yourself, when with them, as among the patients of Bedlam, needing medical more than moral counsel. Be a listener only, keep within yourself, and endeavor to establish with yourself the habit of silence, especially on politics. In the fevered state of our country, no good can ever result from any attempt to set one of these fiery zealots to rights, either in fact or principle. They are determined as to the facts they will believe, and the opinions on which they will act. Get by them, therefore, as you would by an angry bull; it is not for a man of sense to dispute the road with such an animal.”

“A library book lasts as long as a house, for hundreds of years. It is not an article for mere consumption, but fairly of capital, and often in the case of professional men, setting out in life, it is their only capital.”

“With your talents and industry, with science, and that steadfast honesty, which eternally pursues right, regardless of consequences, you may promise yourself everything but health, without which there is no happiness.”

“I have the consolation of having added nothing to my private fortune during my public service, and of retiring with hands clean as they are empty.”

“I am convinced our own happiness requires that we should continue to mix with the world, and to keep pace with it as it goes. "

“If you want something you’ve never had, you’ve got to do something you’ve never done before.”

“Enlighten the people generally, and tyranny and opressions of the body and mind will vanish like evil spirits at the dawn of day.”

“A morsel of genuine history is a thing so rare as to be always valuable.”

“There is a ripeness of time for death,  regarding others as well as ourselves, when it is reasonable we should drop off, and make room for  another growth. When we have lived our generation out, we should not wish to encroach on another.”

“Books constitute capital. A library book lasts as long as a house, for hundreds of years. It is not, then, an article of mere consumption but fairly of capital, and often in the case of professional men, setting out in life, it is their only capital.”

“All that is necessary for a student is access to a library.”

“When injustice becomes law, resistance becomes duty.”

“I would rather be exposed to the inconveniences attending too much liberty, than those attending too small a degree of it.”

“They (religions) dread the advance of science as witches do the approach of daylight and scowl on the fatal harbinger announcing the subversions of the duperies on which they live.”

“The Tree of Liberty must be refreshed from time to time with the blood of patriots and tyrant. It is its natural manure.”