“I have observed, indeed, generally, that while in protestant countries the defections from the Platonic Christianity of the priests is to Deism, in catholic countries they are to Atheism. Diderot, D'Alembert, D’Holbach, Condorcet, are known to have been among the most virtuous of men. Their virtue, then, must have had some other foundation than the love of God.

“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.” 

“If you want something you've never had You must be willing to do something you've never done.” 

“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]” 

“Honesty is the first chapter in the book of wisdom.” 

“And can the liberties of a nation be thought secure when we have removed their only firm basis, a conviction in the minds of the people that these liberties are the gift of God? That they are not to be violated but with His wrath? Indeed, I tremble for my country when I reflect that God is just; that his justice cannot sleep forever.”

“If all be true that I do think, there are five reasons we should drink. Good friends, good times, or being dry, or lest we should be by and by, or any other reason why”

“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. But to return again to our subject.” 

“I cannot live without books . . .”

“I am mortified to be told that, in the United States of America, the sale of a book can become a subject of inquiry, and of criminal inquiry too. ”

“I am a great believer in luck, and I find the harder I work, the more I have of it.”

“Happiness is not being pained in body or troubled in mind.”

“But every difference of opinion is not a difference of principle.”

“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.

“Some men look at constitutions with sanctimonious reverence, and deem them like the ark of the covenant, too sacred to be touched. They ascribe to the men of the preceding age a wisdom more than human, and suppose what they did to be beyond amendment...But I know also, that laws and institutions must go hand in hand with the progress of the human mind. As that becomes more developed, more enlightened, as new discoveries are made, new truths disclosed, and manners and opinions change with the change of circumstances, institutions must advance also, and keep pace with the times.”