“The object most interesting to me for the residue of my life, will be to see you both developing daily those principles of virtue and goodness which will make you valuable to others and happy in yourselves, and acquiring those talents and that degree of science which will guard you at all times against ennui, the most dangerous poison of life. A mind always employed is always happy. This is the true secret, the grand recipe for felicity....In a world which furnishes so many employments which are useful, and so many which are amusing, it is our own fault if we ever know what ennui is...”

“When the subject is strong, simplicity is the only way to treat it.” 

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

“I write nothing for publication, and last of all things should it be on the subject of religion. On the dogmas of religion as distinguished from moral principles, all mankind, from the beginning of the world to this day, have been quarrelling, fighting, burning and torturing one another, for abstractions unintelligible to themselves and to all others, and absolutely beyond the comprehension of the human mind. Were I to enter on that arena, I should only add an unit to the number of Bedlamites.

“Neither Pagan nor Mahamedan nor Jew ought to be excluded from the civil rights of the Commonwealth because of his religion. -quoting John Locke's argument.”

“I agree with yours of the 22d that a professorship of Theology should have no place in our institution. but we cannot always do what is absolutely best. those with whom we act, entertaining different views, have the power and the right of carrying them into practice. truth advances, & error recedes step by step only; and to do to our fellow-men the most good in our power, we must lead where we can, follow where we cannot, and still go with them, watching always the favorable moment for helping them to another step.

“Peace, that glorious moment in time when everyone stops and reloads.”

“A morsel of genuine history is a thing so rare as to be always valuable.”

“Good wine is a necessity of life for me. ”

“Our country is now taking so steady a course as to show by what road it will pass to destruction, to wit: by consolidation of power first, and then corruption, its necessary consequence.”

“Even in Europe a change has sensibly taken place in the mind of man. Science has liberated the ideas of those who read and reflect, and the American example has kindled feelings of right in the people.”

“A nation which expects to be ignorant and free, in a state of civilization, expects that which never was and never will be.”

“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.” 

“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.”

“Whenever you do a thing, act as if all the world were watching.”