“Politics, like religion, hold up the torches of martyrdom to the reformers of error.”

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

“The whole commerce between master and slave is a perpetual exercise of the most boisterous passions, the most unremitting despotism on the one part, and degrading subjugation on the other. Our children see this, and learn to imitate it: for man is an imitative animal.”

“Nothing was or is farther from my intentions, than to enlist myself as the champion of a fixed opinion, where I have only expressed doubt.”

“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.” 

“Men have differed in opinion, and been divided into parties by these opinions, from the first origin of societies; and in all governments where they have been permitted freely to think and to speak. the same political parties which now agitate the U.S. have existed through all time. Whether the power of the people, or that of the (best men; nobles) should prevail, were questions which kept the states of Greece and rome in eternal convulsions...” 

“… 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 and errors.”

“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.”

“You have heard of the new chemical nomenclature endeavored to be introduced by Lavoisier, Fourcroy, &c. Other chemists of this country, of equal note, reject it, and prove in my opinion that it is premature, insufficient and false. These latter are joined by the British chemists; and upon the whole, I think the new nomenclature will be rejected, after doing more harm than good. There are some good publications in it, which must be translated into the ordinary chemical language before they will be useful.”

“That liberty [is pure] which is to go to all, and not to the few or the rich alone. (to Horatio Gates, 1798)”

“Determine never to be idle. No person will have occasion to complain of the want of time, who never loses any. It is wonderful how much may be done, if we are always doing.”

“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.

“The most valuable of all talents is that of never using two words when one will do.”

“Our civil rights have no dependence on our religious opinions any more than our opinions in physics or geometry...”

“The poor who have neither property, friends, nor strength to labor are boarded in the houses of good farmers, to whom a stipulated sum is annually paid. To those who are able to help themselves a little or have friends from whom they derive some succor, inadequate however to their full maintenance, supplementary aids are given which enable them to live comfortably in their own houses or in the houses of their friends. Vagabonds without visible property or vocation, are placed in work houses, where they are well clothed, fed, lodged, and made to labor”