“Never spend your money before you have earned it.”

“I am increasingly persuaded that the earth belongs exclusively to the living and that one generation has no more right to bind another to it's laws and judgments than one independent nation has the right to command another.”

“To compel a man to furnish funds for the propagation of ideas he disbelieves and abhors is sinful and tyrannical.”

“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]” 

“our civil rights have no dependance on our religious opinions, any more than our opinions in physics or geometry; that therefore the proscribing any citizen as unworthy the public confidence by laying upon him an incapacity of being called to offices of trust and emolument, unless he profess or renounce this or that religious opinion, is depriving him injuriously of those privileges and advantages to which, in common with his fellow citizens, he has a natural right; that it tends also to corrupt the principles of that very religion it is meant to encourage,”

“Resolved ... that it would be a dangerous delusion were a confidence in the men of our choice to silence our fears for the safety of our rights: that confidence is everywhere the parent of despotism — free government is founded in jealousy, and not in confidence;”

“Where the preamble declares that coercion is a departure from the plan of the holy author of our religion, an amendment was proposed, by inserting the word "Jesus Christ," so that it should read "a departure from the plan of Jesus Christ, the holy author of our religion." The insertion was rejected by a great majority, in proof that they meant to comprehend, within the mantle of it's protection, the Jew and the Gentile, the Christian and Mahometan, the Hindoo, and infidel of every denomination.”

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

“There is a natural aristocracy among men. The grounds of this are virtue and talents.”

“I find that the harder I work, the more luck I seem to have.”

“Do you want to know who you are? Don't ask. Act! Action will delineate and define you.”

“Those who expect to be both ignorant and free, expect what never was and never will be.” 

“The object most interesting to me for the residue of my life, will be to see you both developing daily those principles of virtue and goodness which will make you valuable to others and happy in yourselves, and acquiring those talents and that degree of science which will guard you at all times against ennui, the most dangerous poison of life. A mind always employed is always happy. This is the true secret, the grand recipe for felicity....In a world which furnishes so many employments which are useful, and so many which are amusing, it is our own fault if we ever know what ennui is...”

“They (religions) dread the advance of science as witches do the approach of daylight and scowl on the fatal harbinger announcing the subversions of the duperies on which they live.”

“Ridicule is the only weapon which can be used against unintelligible propositions.”