“our civil rights have no dependance on our religious opinions, any more than our opinions in physics or geometry; that therefore the proscribing any citizen as unworthy the public confidence by laying upon him an incapacity of being called to offices of trust and emolument, unless he profess or renounce this or that religious opinion, is depriving him injuriously of those privileges and advantages to which, in common with his fellow citizens, he has a natural right; that it tends also to corrupt the principles of that very religion it is meant to encourage,”

“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.”

“He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me.” 

“Every generation needs a new revolution.”

“Some are whigs, liberals, democrats, call them what you please. Others are tories, serviles, aristocrats, &c. The latter fear the people, and wish to transfer all power to the higher classes of society; the former consider the people as the safest depository of power in the last resort; they cherish them therefore, and wish to leave in them all the powers to the exercise of which they are competent.”

“As you say of yourself, I too am an Epicurean. I consider the genuine (not the imputed) doctrines of Epicurus as containing everything rational in moral philosophy which Greece and Rome have left us.

“In matters of principal stand like a rock.”

“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 think one travels more usefully when they travel alone, because they reflect more."

“The rights hereby asserted are of the natural rights of mankind, and that if any act shall be hereafter passed to repeal the present or to narrow its operation, such act will be an infringement of natural right.”

“I am not a Federalist because I never submitted the whole system of my opinions to the creed of any party of men whatever....Such an addiction is the last degradation of a free and moral agent. If I could not go to heaven but with a party, I would not go there at all.”

“They (religions) dread the advance of science as witches do the approach of daylight and scowl on the fatal harbinger announcing the subversions of the duperies on which they live.”

“Nothing gives one person so much advantage over another as to remain always cool and unruffled under all circumstances.”

“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”

“Honesty is the first chapter in the book of wisdom.”