“Be polite to all, but intimate with few.”

“Leave all the afternoon for exercise and recreation, which are as necessary as reading. I will rather say more necessary because health is worth more than learning.”

“I set out on this ground, which I suppose to be self-evident, that the dart belongs in usufruct to the living.”

“I would rather be exposed to the inconveniences attending too much liberty, than those attending too small a degree of it.”

“The executive power in our government is not the only, perhaps not even the principal, object of my solicitude. The tyranny of the legislature is really the danger most to be feared, and will continue to be so for many years to come. The tyranny of the executive power will come in its turn, but at a more distant period.” 

“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]” 

“The fantastical idea of virtue and the public good being a sufficient security to the state against the commission of crimes...was never mine. It is only the sanguinary hue of our penal laws which I meant to object to. Punishments I know are necessary, and I would provide them strict and inflexible, but proportioned to the crime. Death might be inflicted for murder and perhaps for treason, [but I] would take out of the description of treason all crimes which are not such in their nature. Rape, buggery, etc., punish by castration. All other crimes by working on high roads, rivers, gallies, etc., a certain time proportioned to the offence... Laws thus proportionate and mild should never be dispensed with. Let mercy be the character of the lawgiver, but let the judge be a mere machine. The mercies of the law will be dispensed equally and impartially to every description of men; those of the judge or of the executive power will be the eccentric impulses of whimsical, capricious designing man.”

“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.” 

“Whenever the people are well-informed, they can be trusted with their own government”

“As new discoveries are made, new truths discovered and manners and opinions change with the change of circumstances, institutions must advance also to keep pace with the times.”

“No free man shall ever be debarred the use of arms.”

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

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

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

“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.”