“Experience declares that man is the only animal which devours his own kind; for I can apply no milder term to the governments of Europe, and to the general prey of the rich on the poor.”

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

“Do you want to know who you are? Don't ask. Act! Action will delineate and define you.”

“To the corruptions of christianity I am indeed opposed; but not to the genuine precepts of Jesus himself. I am a Christian in the only sense in which he wished any one to be; sincerely attached to his doctrines, in preference to all others; ascribing to himself every human excellence, and believing he never claimed any other.”

“Some men look at constitutions with sanctimonious reverence, and deem them like the ark of the covenant, too sacred to be touched. They ascribe to the men of the preceding age a wisdom more than human, and suppose what they did to be beyond amendment...But I know also, that laws and institutions must go hand in hand with the progress of the human mind. As that becomes more developed, more enlightened, as new discoveries are made, new truths disclosed, and manners and opinions change with the change of circumstances, institutions must advance also, and keep pace with the times.”

“Timid men prefer the calm of despotism to the tempestuous sea of Liberty.”

“Nothing was or is farther from my intentions, than to enlist myself as the champion of a fixed opinion, where I have only expressed doubt.”

“When injustice becomes law, resistance becomes duty.”

“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.”

“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]” 

“The whole commerce between master and slave is a perpetual exercise of the most boisterous passions, the most unremitting despotism on the one part, and degrading subjugation on the other. Our children see this, and learn to imitate it: for man is an imitative animal.”

“Never spend your money before you have it.”

“A strict observance of the written laws is doubtless one of the highest virtues of a good citizen, but it is not the highest. The laws of necessity, of self-preservation, of saving our country when in danger, are of higher obligation. To lose our country by a scrupulous adherence to written law would be to lose the law itself, with life, liberty, property and all those who are enjoying them with us; thus absurdly sacrificing the end to the means.”

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

“You seem to consider the judges as the ultimate arbiters of all constitutional questions; a very dangerous doctrine indeed, and one which would place us under the despotism of an oligarchy. Our judges are as honest as other men, and not more so. They have, with others, the same passions for party, for power, and the privilege of their corps.... Their power [is] the more dangerous as they are in office for life, and not responsible, as the other functionaries are, to the elective control. The Constitution has erected no such single tribunal, knowing that to whatever hands confided, with the corruptions of time and party, its members would become despots. It has more wisely made all the departments co-equal and co-sovereign within themselves.”