“Too old to plant trees for my own gratification, I shall do it for my posterity.”

“A government big enough to give you everything you want, is strong enough to take everything you have

“I am certainly not an advocate for frequent and untried changes in laws and constitutions. I think moderate imperfections had better be borne with; because, when once known, we accommodate ourselves to them, and find practical means of correcting their ill effects. 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. We might as well require a man to wear still the coat which fitted him when a boy, as civilized society to remain ever under the regimen of their barbarous ancestors.”

“The happiest moments of my life have been the few which I have passed at home in the bosom of my family.”

“If all be true that I do think, there are five reasons we should drink. Good friends, good times, or being dry, or lest we should be by and by, or any other reason why”

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

“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]” 

“Every generation needs a new revolution.”

“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.” 

“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.”

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

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

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

“Self-love is no part of morality. Indeed it is exactly its counterpart. It is the sole antagonist of virtue leading us constantly by our propensities to self-gratification in violation of our moral duties to others.”

“...We are all Federalists,and we are all Republicans.”