“I never considered a difference of opinion in politics, in religion, in philosophy, as cause for withdrawing from a friend.” 

“I would rather be exposed to the inconveniences attending too much liberty, than those attending too small a degree of it.”

“Peace, commerce, and honest friendship with all nations...entangling alliances with none”

“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 have the consolation of having added nothing to my private fortune during my public service, and of retiring with hands clean as they are empty.”

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

“All tyranny needs to gain a foothold is for people of good conscience to remain silent.”

“I have sworn upon the altar of god, eternal hostility against every form of tyranny over the mind of man.”

“Freedom, the first-born of science.”

“I never will, by any word or act, bow to the shrine of intolerance or admit a right of inquiry into the religious opinions of others.”

“Never trouble another for what you can do yourself”

“We in America do not have government by the majority. We have government by the majority who participate.”

“Question with boldness even the existence of a God; because, if there be one, he must more approve of the homage of reason, than that of blind-folded fear.”

“Our greatest happiness does not depend on the condition of life in which chance has placed us, but is always the result of a good conscience, good health, occupation, and freedom in all just pursuits.”

“The attempt of Lavoisier to reform chemical nomenclature is premature. One single experiment may destroy the whole filiation of his terms; and his string of sulphates, sulphites, and sulphures, may have served no end than to have retarded the progress of science by a jargon, from the confusion of which time will be requisite to extricate us.”