“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...”

“never trust a man who won't accept that there is more than one way to spell a word Paraphrased”

“He who knows best knows how little he knows.”

“Our country is too large to have all its affairs directed by a single government. Public servants at such a distance, and from under the eye of their constituents, must, from the circumstance of distance, be unable to administer and overlook all the details necessary for the good government of the citizens; and the same circumstance, by rendering detection impossible to their constituents, will invite public agents to corruption, plunder and waste.”

“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]” 

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

“He who permits himself to tell a lie once, finds it much easier to do it the second time.”

“Kejujuran merupakan suatu kebijakan dalam bisnis, yang tidak perlu diubah atau disesuaikan dengan waktu.” 

“I cannot live without books . . .”

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

“A habilidade mais valiosa é aquela de jamais usar duas palavras quando uma apenas basta.”

“And for the support of this declaration, with a firm reliance on the protection of divine providence, we mutually pledge to each other our lives, our fortunes and our sacred honor.”

“I hope we shall ... crush in it’s birth the aristocracy of our monied corporations which dare already to challenge our government to a trial of strength, and to bid defiance to the laws of their country.”

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

“The art of life is the art of avoiding pain.”