“Nothing is more likely than that [the] enumeration of powers is defective. This is the ordinary case of all human works. Let us then go on perfecting it by adding by way of amendment to the Constitution those powers which time and trial show are still wanting”

“The inquisition of public opinion overwhelms in practice the freedom asserted by the laws in theory.”

“Experience hath shewn, that even under the best forms, those entrusted with power have, in time, and by slow operations, perverted it into tyranny; and it is believed that the most effectual means of preventing this would be, to illuminate, as far as practicable, the minds of the people at large...”

“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 art of government consists in the art of being honest.”

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

“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.”

“Speaking one day to Monsieur de Buffon, on the present ardor of chemical inquiry, he affected to consider chemistry but as cookery, and to place the toils of the laboratory on the footing with those of the kitchen. I think it, on the contrary, among the most useful of sciences, and big with future discoveries for the utility and safety of the human race.”

“We in America do not have government by the majority. We have government by the majority who participate.”

“Perceiving the order of nature to be that individual happiness shall be inseparable from the practice of virtue, I am willing to hope it may have ordained that the fall of the wicked shall be the rise of the good.  To J. Correa de Serra, Monticello, Apr. 19, 1814”

“The truth is that the greatest enemies to the doctrines of Jesus are those calling themselves the expositors of them, who have perverted them for the structure of a system of fancy absolutely incomprehensible, and without any foundation in his genuine words. And the day will come when the mystical generation of Jesus by the supreme being as his father in the womb of a virgin will be classed with the fable of the generation of Minerva in the brain of Jupiter, but we may hope that the dawn of reason and freedom of thought in these United States will do away with all this artificial scaffolding and restore to us the primitive and genuine doctrines of this, the most venerated reformer of human errors. -Thomas Jefferson to John Adams (April 11, 1823)” 

“The dead should not rule the living.”

“So inscrutable is the arrangement of causes and consequences in this world, that a two-penny duty on tea, unjustly imposed in a sequestered part of it, changes the condition of all its inhabitants.”

“I cannot live without books: but fewer will suffice where amusement, and not use, is the only future object.” 

“When the clergy addressed General Washington on his departure from the government, it was observed in their consultation that he had never on any occasion said a word to the public which showed a belief in the Christian religion and they thought they should so pen their address as to force him at length to declare publicly whether he was a Christian or not. They did so. However [Dr. Rush] observed the old fox was too cunning for them. He answered every article of their address particularly except that, which he passed over without notice... I know that Gouverneur Morris, who pretended to be in his secrets & believed himself to be so, has often told me that General Washington believed no more of that system than he himself did.