“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;”

“The people cannot be all, and always, well informed. The part which is wrong will be discontented, in proportion to the importance of the facts they misconceive. If they remain quiet under such misconceptions, it is lethargy, the forerunner of death to the public liberty. ... What country before ever existed a century and half without a rebellion? And what country can preserve its liberties if their rulers are not warned from time to time that their people preserve the spirit of resistance? Let them take arms. The remedy is to set them right as to facts, pardon and pacify them. What signify a few lives lost in a century or two? The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants. It is its natural manure.”

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

“Peace and friendship with all mankind is our wisest policy, and I wish we may be permitted to pursue it.”

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

“All is safe where all can read," is a quotation from Thomas Jefferson showing his belief in the importance of everyone knowing how to and being able/allowed to read. I would like to take it one step further.  I would say, "All is BETTER when all can read." No matter what you like to read, the ability to read it, understand it, and enjoy it, truly enriches your life.”

“When injustice becomes law, resistance becomes duty.”

“The attempt of Lavoisier to reform chemical nomenclature is premature. One single experiment may destroy the whole filiation of his terms; and his string of sulphates, sulphites, and sulphures, may have served no end than to have retarded the progress of science by a jargon, from the confusion of which time will be requisite to extricate us.” 

“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.” 

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

“The main objects of all science, the freedom and happiness of man. . . . [are] the sole objects of all legitimate government.

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

“Can the liberties of a nation be thought secure when we have removed their only firm basis, a conviction in the minds of people that these liberties are the gift of God?” 

“no people can be both ignorant and free.”