“There is not a truth existing which I fear, or would wish unknown to the whole world.”

“While the art of printing is left to us science can never be retrograde; what is once acquired of real knowledge can never be lost.”

“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.”

“It is the duty of every American citizen to take part in a vigorous debate on the issues of the day.”

“History, by apprising [the people] of the past, will enable them to judge of the future.” 

“Our civil rights have no dependence upon our religious opinions more than our opinions in physics or geometry.”

“سلطة ضخمة و قوية جدا توفر لك كل ما تطلبه ، هى حكومة قادرة على سلب كل شئ منك . التاريخ يقول انه كلما زادت قوة السلطات نقصت الحرية”

“I think one travels more usefully when they travel alone, because they reflect more."

“Pride costs us more than hunger, thirst, and cold.”

“Freedom, the first-born of science.”

“Commerce with all nations, alliance with none, should be our motto.”

“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]” 

“Question with boldness even the existence of a God; because, if there be one, he must more approve of the homage of reason, than that of blind-folded fear.”

“The probable accumulation of the surpluses of revenue beyond what can be applied to the payment of the public debt... merits the consideration of Congress. Shall it lie unproductive in the public vaults?...Or shall it rather be appropriated to the improvements of roads, canals, rivers, education, and other great foundations of prosperity and union”

“But every difference of opinion is not a difference of principle.”