“Difference of opinion is advantageous in religion. The several sects perform the office of a Censor morum over each other. Is uniformity attainable? Millions of innocent men, women, and children, since the introduction of Christianity, have been burnt, tortured, fined, imprisoned; yet we have not advanced one inch towards uniformity. What has been the effect of coercion? To make one half the world fools, and the other half hypocrites. To support roguery and error all over the earth. Let us reflect that it is inhabited by a thousand millions of people. That these profess probably a thousand different systems of religion. That ours is but one of that thousand. That if there be but one right, and ours that one, we should wish to see the 999 wandering sects gathered into the fold of truth. But against such a majority we cannot effect this by force. Reason and persuasion are the only practicable instruments. To make way for these, free enquiry must be indulged; and how can we wish others to indulge it while we refuse it ourselves.”

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

“On matters of style, swim with the current, on matters of principle, stand like a rock.”

“To the corruptions of Christianity I am, indeed opposed; but not to the genuine precepts of Jesus himself. I am a Christian, in the only sense in which he wished any one to be; sincerely attached to his doctrines, in preference to all others.”

“Commerce with all nations, alliance with none, should be our motto.”

“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]” 

“If there be any among us who would wish to dissolve this Union, or to change its republican form, let them stand undisturbed as monuments of the safety with which error of opinion may be tolerated, where reason is left free to combat it."

“when you come to the end of your rope, tie a knot and hang on”

“I have often thought that nothing would do more extensive good at small expense than the establishment of a small circulating library in every county, to consist of a few well-chosen books, to be lent to the people of the country under regulations as would secure their safe return in due time.”

“He has erected a multitude of New Offices, and sent hither swarms of Officers to harass our People, and eat out their substance.”

“If by religion we are to understand sectarian dogmas, in which no two of them agree, then your exclamation on that hypothesis is just, "that this would be the best of worlds if there were no religion in it.” 

“Of all machines, the human heart is the most complicated and inexplicable.”

“May it [American independence] be to the world, what I believe it will be, (to some parts sooner, to others later, but finally to all,) the signal of arousing men to burst the chains under which monkish ignorance and superstition had persuaded them to bind themselves, and to assume the blessings and security of self-government. That form which we have substituted, restores the free right to the unbounded exercise of reason and freedom of opinion. All eyes are opened, or opening, to the rights of man. The general spread of the light of science has already laid open to every view the palpable truth, that the mass of mankind has not been born with saddles on their backs, nor a favored few booted and spurred, ready to ride them legitimately... These are grounds of hope for others. For ourselves, let the annual return of this day forever refresh our recollections of these rights, and an undiminished devotion to them.

“I sincerely believe that banking establishments are more dangerous than standing armies, and that the principle of spending money to be paid by posterity, under the name of funding, is but swindling futurity on a large scale.”

“I have lived temperately, eating little animal food, and that not as an aliment, so much as a condiment for the vegetables, which constitute my principal diet.”