“History, I believe, furnishes no example of a priest-ridden people maintaining a free civil government. This marks the lowest grade of ignorance of which their civil as well as religious leaders will always avail themselves for their own purposes.

“The policy of the American government is to leave its citizens free, neither restraining them nor aiding them in their pursuits.”

“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. ”

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

“I am convinced our own happiness requires that we should continue to mix with the world, and to keep pace with it as it goes. "

“I believe that banking institutions are more dangerous to our liberties than standing armies.” 

“the measure of society is how it treats the weakest members”

“How much pain they have cost us, the evils which have never happened. --”

“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.” 

“Truth is great and will prevail if left to herself.”

“I have indeed two great measures at heart, without which no republic can maintain itself in strength: 1. That of general education, to enable every man to judge for himself what will secure or endanger his freedom. 2. To divide every county into hundreds, of such size that all the children of each will be within reach of a central school in it”

“The whole art of government consists in the art of being honest. Only aim to do your duty, and mankind will give you credit where you fail.”

“Nothing is more likely than that [the] enumeration of powers is defective. This is the ordinary case of all human works. Let us then go on perfecting it by adding by way of amendment to the Constitution those powers which time and trial show are still wanting”

“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]” 

“A morsel of genuine history is a thing so rare as to be always valuable.”