“In every country and in every age, the priest has been hostile to liberty. He is always in alliance with the despot, abetting his abuses in return for protection to his own.”

“We are afraid of the known and afraid of the unknown. That is our daily life and in that there is no hope, and therefore every form of philosophy, every form of theological concept, is merely an escape from the actual reality of what is. All outward forms of change brought about by wars, revolutions, reformations, laws and ideologies have failed completely to change the basic nature of man and therefore of society.”

“I cannot live without books: but fewer will suffice where amusement, and not use, is the only future object.” 

“Were it left to me to decide whether we should have a government without newspapers or newspapers without a government, I should not hesitate a moment to prefer the latter.”

“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 care of human life and happiness, and their destruction is the first and only legitimate object of a good government.”

“Reason and free inquiry are the only effectual agents against error.”

“A strong body makes the mind strong. As to the species of exercises, I advise the gun. While this gives moderate exercise to the body, it gives boldness, enterprise and independence to the mind. Games played with the ball and others of that nature are too violent for the body and stamp no character on the mind. Let your gun therefore be your constant companion of your walks.”

“With your talents and industry, with science, and that steadfast honesty, which eternally pursues right, regardless of consequences, you may promise yourself everything but health, without which there is no happiness.”

“I have observed, indeed, generally, that while in protestant countries the defections from the Platonic Christianity of the priests is to Deism, in catholic countries they are to Atheism. Diderot, D'Alembert, D’Holbach, Condorcet, are known to have been among the most virtuous of men. Their virtue, then, must have had some other foundation than the love of God.

“If there is one principle more deeply rooted in the mind of every American, it is that we should have nothing to do with conquest.”

“I consider him [Alexander von Humboldt] the most important scientist whom I have met.”

“Perceiving the order of nature to be that individual happiness shall be inseparable from the practice of virtue, I am willing to hope it may have ordained that the fall of the wicked shall be the rise of the good.  To J. Correa de Serra, Monticello, Apr. 19, 1814”

“Experience declares that man is the only animal which devours his own kind; for I can apply no milder term to the governments of Europe, and to the general prey of the rich on the poor.”

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