“The most fortunate of us, in our journey through life, frequently meet with calamities and misfortunes which may greatly afflict us; and, to fortify our minds against the attacks of these calamities and misfortunes should be one of the principal studies and endeavors of our lives. The only method of doing this is to assume a perfect resignation to the Divine will, to consider that whatever does happen, must happen; and that, by our uneasiness, we cannot prevent the blow before it does fall, but we may add to its force after it has fallen. These considerations, and others such as these, may enable us in some measure to surmount the difficulties thrown in our way; to bear up with a tolerable degree of patience under the burden of life; and to proceed with a pious and unshaken resignation, till we arrive at our journey's end.”

“I almost shudder at the thought of alluding to the most fatal example of the abuses of grief which the history of mankind has preserved - the Cross. Consider what calamities that engine of grief has produced! With the rational respect that is due to it, knavish priests have added prostitutions of it, that fill or might fill the blackest and bloodiest pages of human history.

“The opinions and beliefs of men follow involuntarily the evidence proposed to their minds.”

“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]” 

“Later, he told his nephew that religion required careful thought, not reflexive acceptance. "Fix reason firmly in her seat, and call to her tribunal every fact, every opinion. Question with boldness even the existence of a God; because, if there be one, he must more approve the homage of reason, than that of blindfolded fear”

“I predict future happiness for Americans, if they can prevent the government from wasting the labors of the people under the pretense of taking care of them.” 

“Bigotry is the disease of ignorance, of morbid minds; enthusiasm of the free and buoyant. Education and free discussion are the antidotes of both. We are destined to be a barrier against the returns of ignorance and barbarism. Old Europe will have to lean on our shoulders, and to hobble along by our side, under the monkish trammels of priests and kings, as she can. What a Colossus shall we be when the Southern continent comes up to our mark! What a stand will it secure as a ralliance for the reason & freedom of the globe! I like the dreams of the future better than the history of the past. So good night. I will dream on, always fancying that Mrs Adams and yourself are by my side marking the progress and the obliquities of ages and countries.”

“Nobody is better than you and remember, you are better than nobody.

“I prefer dangerous freedom over peaceful slavery.”

“If the present Congress errs in too much talking, how can it be otherwise in a body to which the people send 150 lawyers, whose trade it is to question everything, yield nothing, & talk by the hour? That 150 lawyers should do business together ought not to be expected.”

“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...” 

“I agree with yours of the 22d that a professorship of Theology should have no place in our institution. but we cannot always do what is absolutely best. those with whom we act, entertaining different views, have the power and the right of carrying them into practice. truth advances, & error recedes step by step only; and to do to our fellow-men the most good in our power, we must lead where we can, follow where we cannot, and still go with them, watching always the favorable moment for helping them to another step.

“The rich alone use imported articles, and on these alone the whole taxes of the General Government are levied...and its surplus applied to canals, roads, schools, etc., the farmer will see his government supported, his children educated, and the face of his country made a paradise by the contributions of the rich alone, without his being called on to spend a cent from his earnings.”

“Leave no authority existing not responsible to the people.”

“He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me.”