“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”

“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 received the favor of your letter of August 17th, and with it the volume you were so kind as to send me on the Literature of Negroes. Be assured that no person living wishes more sincerely than I do, to see a complete refutation of the doubts I have myself entertained and expressed on the grade of understanding allotted to them by nature, and to find that in this respect they are on a par with ourselves. My doubts were the result of personal observation on the limited sphere of my own State, where the opportunities for the development of their genius were not favorable, and those of exercising it still less so. I expressed them therefore with great hesitation; but whatever be their degree of talent it is no measure of their rights. Because Sir Isaac Newton was superior to others in understanding, he was not therefore lord of the person or property of others. On this subject they are gaining daily in the opinions of nations, and hopeful advances are making towards their reestablishment on an equal footing with the other colors of the human family.”

“...as we advance in life these things fall off one by one , and I suspect we are left with only Homer and Virgil, perhaps with only Homer alone.”

“The care of human life and happiness, and their destruction is the first and only legitimate object of a good government.”

“he repudiated the writings of the Apostle Paul," whom he considered the (first corrupter of the doctrines of Jesus”

“A strict observance of the written laws is doubtless one of the highest virtues of a good citizen, but it is not the highest. The laws of necessity, of self-preservation, of saving our country when in danger, are of higher obligation. To lose our country by a scrupulous adherence to written law would be to lose the law itself, with life, liberty, property and all those who are enjoying them with us; thus absurdly sacrificing the end to the means.”

“We believe no more in Bonaparte's fighting merely for the liberties of the seas than in Great Britain's fighting for the liberties of mankind. The object is the same, to draw to themselves the power, the wealth and the resources of other nations.”

“And to preserve their independence, we must not let our rulers load us with perpetual debt. We must make our election between economy and liberty, or profusion and servitude. If we run into such debts, as that we must be taxed in our meat and in our drink, in our necessaries and our comforts, in our labors and our amusements, for our callings and our creeds, as the people of England are, our people, like them, must come to labor sixteen hours in the twenty-four, give the earnings of fifteen of these to the government for their debts and daily expenses; and the sixteenth being insufficient to afford us bread, we must live, as they now do, on oatmeal and potatoes; have no time to think, no means of calling the mismanagers to account; but be glad to obtain subsistence by hiring ourselves to rivet their chains on the necks of our fellow-sufferers.” 

“The glow of one warm thought is to me worth more than money.”

“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.

“Speaking one day to Monsieur de Buffon, on the present ardor of chemical inquiry, he affected to consider chemistry but as cookery, and to place the toils of the laboratory on the footing with those of the kitchen. I think it, on the contrary, among the most useful of sciences, and big with future discoveries for the utility and safety of the human race.”

“Where the preamble declares that coercion is a departure from the plan of the holy author of our religion, an amendment was proposed, by inserting the word "Jesus Christ," so that it should read "a departure from the plan of Jesus Christ, the holy author of our religion." The insertion was rejected by a great majority, in proof that they meant to comprehend, within the mantle of it's protection, the Jew and the Gentile, the Christian and Mahometan, the Hindoo, and infidel of every denomination.”

“If by religion we are to understand sectarian dogmas, in which no two of them agree, then your exclamation on that hypothesis is just, "that this would be the best of worlds if there were no religion in it.” 

“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.”