“yet neither are those innocent who lay the bait in their way; that the opinions of men are not the object of civil government, nor under its jurisdiction; that to suffer the civil magistrate to intrude his powers into the field of opinion and to restrain the profession or propagation of principles on supposition of their ill tendency is a dangerous falacy, which at once destroys all religious liberty, because he being of course judge of that tendency will make his opinions the rule of judgment, and approve or condemn the sentiments of others only as they shall square with or differ from his own; that it is time enough for the rightful purposes of civil government for its officers to interfere when principles break out into overt acts against peace and good order;”

“I had rather be shut up in a very modest cottage with my books, my family and a few old friends, dining on simple bacon, and letting the world roll on as it liked, than to occupy the most splendid post, which any human power can give.”

“[n regard to Jesus believing himself inspired] This belief carried no more personal imputation than the belief of Socrates that he was under the care and admonition of a guardian demon. And how many of our wisest men still believe in the reality of these inspirations while perfectly sane on all other subjects (Works, Vol. iv, p. 327).”

“It is neither wealth nor splendor, but tranquility and occupation which give happiness.”

“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 am not among those who fear the people. They, and not the rich, are our dependence for continued freedom.”

“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”

“Some men look at constitutions with sanctimonious reverence, and deem them like the ark of the covenant, too sacred to be touched. They ascribe to the men of the preceding age a wisdom more than human, and suppose what they did to be beyond amendment. I knew that age well; I belonged to it, and labored with it. It deserved well of its country. It was very like the present, but without the experience of the present; and forty years of experience in government is worth a century of book-reading; and this they would say themselves, were they to rise from the dead. I am certainly not an advocate for frequent and untried changes in laws and constitutions. I think moderate imperfections had better be borne with; because, when once known, we accommodate ourselves to them, and find practical means of correcting their ill effects. But I know also, that laws and institutions must go hand in hand with the progress of the human mind. As that becomes more developed, more enlightened, as new discoveries are made, new truths disclosed, and manners and opinions change with the change of circumstances, institutions must advance also, and keep pace with the times. We might as well require a man to wear still the coat which fitted him when a boy, as civilized society to remain ever under the regimen of their barbarous ancestors.” 

“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. ”

“Everything yields to diligence”

“Later, he told his nephew that religion required careful thought, not reflexive acceptance. "Fix reason firmly in her seat, and call to her tribunal every fact, every opinion. Question with boldness even the existence of a God; because, if there be one, he must more approve the homage of reason, than that of blindfolded fear”

“The opinions of men are not the object of civil government, nor under its jurisdiction.” 

“A government which can be felt; a government of energy. God send that our country may never have a government, which it can feel.”

“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.

“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.