“When once we quit the basis of sensation, all is in the wind. To talk of immaterial existences is to talk of nothings. To say that the human soul, angels, god, are immaterial, is to say they are nothings, or that there is no god, no angels, no soul. I cannot reason otherwise: but I believe I am supported in my creed of materialism by Locke, Tracy, and Stewart.

“He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me. That ideas should freely spread from one to another over the globe, for the moral and mutual instruction of man, and improvement of his condition, seems to have been peculiarly and benevolently designed by nature, when she made them, like fire, expansible over all space, without lessening their density in any point, and like the air in which we breathe, move, and have our physical being, incapable of confinement or exclusive appropriation.”

“Every citizen should be a soldier. This was the case with the Greeks and Romans, and must be that of every free state.”

“...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.”

“Kejujuran merupakan suatu kebijakan dalam bisnis, yang tidak perlu diubah atau disesuaikan dengan waktu.” 

“Do not bite at the bait of pleasure till you know there is no hook beneath it.”

“I do not take a single newspaper, nor read one a month, and I feel myself infinitely the happier for it.” 

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

“A great deal of love given to a few is better than a little to many.”

“I cannot live without books . . .”

“Our country is too large to have all its affairs directed by a single government. Public servants at such a distance, and from under the eye of their constituents, must, from the circumstance of distance, be unable to administer and overlook all the details necessary for the good government of the citizens; and the same circumstance, by rendering detection impossible to their constituents, will invite public agents to corruption, plunder and waste.”

“...as we advance in life these things fall off one by one , and I suspect we are left with only Homer and Virgil, perhaps with only Homer alone.”

“when you come to the end of your rope, tie a knot and hang on”

“It is neither wealth nor splendor; but tranquility and occupation which give you happiness.”

“not to find out new principles, or new arguments, never before thought of . . . but to place before mankind the common sense of the subject, in terms so plain and firm as to command their assent, and to justify ourselves in the independent stand we are compelled to take.”