“Let us save what remains: not by vaults and locks which fence them from the public eye and use in consigning them to the waste of time, but by such a multiplication of copies, as shall place them beyond the reach of accident.”

“The doctor of the future will give no medicine, but will interest his (sic)patient in the care of the human frame, in diet and in the cause and prevention of disease”

“The majority, oppressing an individual, is guilty of a crime, abuses its strength, and by acting on the law of the strongest breaks up the foundations of society.”

“If our house be on fire, without inquiring whether it was fired from within or without, we must try to extinguish it.”

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

“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]” 

“We seem not to perceive that, by the law of nature, one generation is to another as one independent nation is to another.”

“The only security of all is in a free press.”

“Never spend your money before you have earned it.”

“Whenever any form of government becomes destructive of these ends [life, liberty, and the pursuit of happiness] it is the right of the people to alter or abolish it, and to institute new government...” 

“It is an axiom in my mind, that our liberty can never be safe but in the hands of the people themselves, and that too of the people with a certain degree of instruction. This it is the business of the State to effect, and on a general plan.”

“our civil rights have no dependance on our religious opinions, any more than our opinions in physics or geometry; that therefore the proscribing any citizen as unworthy the public confidence by laying upon him an incapacity of being called to offices of trust and emolument, unless he profess or renounce this or that religious opinion, is depriving him injuriously of those privileges and advantages to which, in common with his fellow citizens, he has a natural right; that it tends also to corrupt the principles of that very religion it is meant to encourage,”

“A habilidade mais valiosa é aquela de jamais usar duas palavras quando uma apenas basta.”

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

“In a republican nation, whose citizens are to be led by reason and persuasion and not by force, the art of reasoning becomes of first importance”