“I shall not die without a hope that light and liberty are on a steady advance. Even should the cloud of barbarism and despotism again obscure the science and liberties of Europe, this country remains to preserve and restore light and liberty to them. In, short, the flames kindled on the 4th of July, 1776, have spread over too much of the globe to be extinguished by the feeble engines of despotism; on the contrary, they will consume these and all who work for them.”

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

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

“we commit honest maniacs to Bedlam, so judges should be withdrawn from their bench, whose erroneous biases are leading us to dissolution.”

“To the corruptions of Christianity I am, indeed opposed; but not to the genuine precepts of Jesus himself. I am a Christian, in the only sense in which he wished any one to be; sincerely attached to his doctrines, in preference to all others.”

“The vote being passed, altho' further observn on it was out of order, he could not refrain from rising and expressing his satisfaction and concluded by saying "there is but one word, Mr. President, in the paper which I disapprove, & that is the word Congress," on which Ben Harrison rose and said "there is but on word in the paper, Mr. President, of which I approve, and that is the word Congress.”

“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...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.”

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

“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”

“We are not to expect to be translated from despotism to liberty in a featherbed.”

“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.” 

“We took the liberty to make some enquiries concerning the ground of their pretensions to make war upon nations who had done them no injury, and observed that we considered all mankind as our friends who had done us no wrong, nor had given us any provocation. The Ambassador [of Tripoli] answered us that it was founded on the Laws of their Prophet, that it was written in their Koran, that all nations who should not have acknowledged their authority were sinners, that it was their right and duty to make war upon them wherever they could be found, and to make slaves of all they could take as Prisoners, and that every Musselman who should be slain in battle was sure to go to Paradise.

“The greatest service which can be rendered any country is to add a useful plant to its culture.

“A great deal of love given to a few is better than a little to many.”

“The ground of liberty is to be gained by inches. We must be contented to secure what we can get from time to time and eternally press forward for what is yet to get. It takes time to persuade men to do even what is for their own good.”