“Good humor is one of the preservatives of our peace and tranquility” 

“We took the liberty to make some enquiries concerning the ground of their pretensions to make war upon nations who had done them no injury, and observed that we considered all mankind as our friends who had done us no wrong, nor had given us any provocation. The Ambassador [of Tripoli] answered us that it was founded on the Laws of their Prophet, that it was written in their Koran, that all nations who should not have acknowledged their authority were sinners, that it was their right and duty to make war upon them wherever they could be found, and to make slaves of all they could take as Prisoners, and that every Musselman who should be slain in battle was sure to go to Paradise.

“Men have differed in opinion, and been divided into parties by these opinions, from the first origin of societies; and in all governments where they have been permitted freely to think and to speak. the same political parties which now agitate the U.S. have existed through all time. Whether the power of the people, or that of the (best men; nobles) should prevail, were questions which kept the states of Greece and rome in eternal convulsions...” 

“I cannot live without books . . .”

“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.”

“If we could believe that he [Jesus] really countenanced the follies, the falsehoods, and the charlatanism which his biographers [Gospels] father on him, and admit the misconstructions, interpolations, and theorizations of the fathers of the early, and the fanatics of the latter ages, the conclusion would be irresistible by every sound mind that he was an impostor... We find in the writings of his biographers matter of two distinct descriptions. First, a groundwork of vulgar ignorance, of things impossible, of superstitions, fanaticisms and fabrications... That sect [Jews] had presented for the object of their worship, a being of terrific character, cruel, vindictive, capricious and unjust... Jesus had to walk on the perilous confines of reason and religion: and a step to right or left might place him within the gripe of the priests of the superstition, a blood thirsty race, as cruel and remorseless as the being whom they represented as the family God of Abraham, of Isaac and of Jacob, and the local God of Israel. They were constantly laying snares, too, to entangle him in the web of the law... That Jesus did not mean to impose himself on mankind as the son of God, physically speaking, I have been convinced by the writings of men more learned than myself in that lore.

“The Constitution of most of our states (and of the United States) assert that all power is inherent in the people; that they may exercise it by themselves; that it is their right and duty to be at all times armed.”

“I wish I was a despot that I might save the noble, the beautiful trees that are daily falling sacrifice to the cupidity of their owners, or the necessity of the poor. The unnecessary felling of a tree, perhaps the growth of centuries, seems to me a crime little short of murder.”

“The contest is not between Us and Them, but between Good and Evil, and if those who would fight Evil adopt the ways of Evil, Evil wins.”

“All are dead, and ourselves left alone amidst a new generation whom we know not, and who know us not.”

“A democracy is nothing more than mob rule, where fifty-one percent of the people may take away the rights of the other forty-nine.” 

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

“All should be laid open to you without reserve, for there is not a truth existing which I fear, or would wish unknown to the whole world.” 

“A great deal of love given to a few is better than a little to many.”