“In matters of principal stand like a rock.”

“What a stupendous, what an incomprehensible machine is man! Who can endure toil, famine, stripes, imprisonment and death itself in vindication of his own liberty, and the next moment . . . inflict on his fellow men a bondage, one hour of which is fraught with more misery than ages of that which he rose in rebellion to oppose.”

“I hold it that a little rebellion now and then is a good thing, and as necessary in the political world as storms in the physical. Unsuccesful rebellions indeed generally establish the incroachments on the rights of the people which have produced them. An observation of this truth should render honest republican governors so mild in their punishment of rebellions, as not to discourage them too much. It is a medecine necessary for the sound health of government.”

“Nobody is better than you and remember, you are better than nobody.

“And for the support of this declaration, with a firm reliance on the protection of divine providence, we mutually pledge to each other our lives, our fortunes and our sacred honor.”

“To your request of my opinion of the manner in which a newspaper should be conducted, so as to be most useful, I should answer, ‘by restraining it to true facts & sound principles only.’ Yet I fear such a paper would find few subscribers. It is a melancholy truth, that a suppression of the press could not more compleatly deprive the nation of its benefits, than is done by its abandoned prostitution to falsehood. Nothing can now be believed which is seen in a newspaper. Truth itself becomes suspicious by being put into that polluted vehicle. The real extent of this state of misinformation is known only to those who are in situations to confront facts within their knolege with the lies of the day. I really look with commiseration over the great body of my fellow citizens, who, reading newspapers, live & die in the belief, that they have known something of what has been passing in the world in their time; whereas the accounts they have read in newspapers are just as true a history of any other period of the world as of the present, except that the real names of the day are affixed to their fables. General facts may indeed be collected from them, such as that Europe is now at war, that Bonaparte has been a successful warrior, that he has subjected a great portion of Europe to his will, &c., &c.; but no details can be relied on. I will add, that the man who never looks into a newspaper is better informed than he who reads them; inasmuch as he who knows nothing is nearer to truth than he whose mind is filled with falsehoods & errors. He who reads nothing will still learn the great facts, and the details are all false.” —Letter to John Norvell, 14 June 1807 [Works 10:417--18]” 

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

“Even in Europe a change has sensibly taken place in the mind of man. Science has liberated the ideas of those who read and reflect, and the American example has kindled feelings of right in the people.”

“Nature intended me for the tranquil pursuits of science, by rendering them my supreme delight. But the enormities of the times in which I have lived, have forced me to take a part in resisting them, and to commit myself on the boisterous ocean of political passions.”

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

“I haven't failed. I've just found 10,000 ways that don't work.”

“The bill for establishing religious freedom, the principles of which had, to a certain degree, been enacted before, I had drawn in all the latitude of reason & right. It still met with opposition; but, with some mutilations in the preamble, it was finally passed; and a singular proposition proved that it's protection of opinion was meant to be universal. Where the preamble declares that coercion is a departure from the plan of the holy author of our religion, an amendment was proposed, by inserting the word "Jesus Christ," so that it should read "a departure from the plan of Jesus Christ, the holy author of our religion." The insertion was rejected by a great majority, in proof that they meant to comprehend, within the mantle of it's protection, the Jew and the Gentile, the Christian and Mahometan, the Hindoo, and infidel of every denomination.”

“No occupation is so delightful to me as the culture of the earth, no culture comparable to that of the garden...But though an old man, I am but a young gardener.”

“Politics, like religion, hold up the torches of martyrdom to the reformers of error.”

“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. Inventions then cannot, in nature, be a subject of property.”