“Whenever any form of government becomes destructive of these ends [life, liberty, and the pursuit of happiness] it is the right of the people to alter or abolish it, and to institute new government...” 

“I hold it that a little rebellion now and then is a good thing, and as necessary in the political world as storms in the physical.” 

“I hold it that a little rebellion now and then is a good thing, and as necessary in the political world as storms in the physical. Unsuccesful rebellions indeed generally establish the incroachments on the rights of the people which have produced them. An observation of this truth should render honest republican governors so mild in their punishment of rebellions, as not to discourage them too much. It is a medecine necessary for the sound health of government.”

“If Americans desire to be both ignorant and free, they want what never has been and what 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.” 

“I am conscious that an equal division of property is impracticable. But the consequences of this enormous inequality [in Europe] producing so much misery to the bulk of mankind, legislators cannot invent too many devices for subdividing property,...[One] means of silently lessening the inequality of property is to exempt all from taxation below a certain point, and to tax the higher portions of property in geometrical progression as they rise.”

“all experience hath shewn, that mankind are more disposed to suffer, while evils are sufferable, than to right themselves by abolishing the forms to which they are accustomed.”

“No man will ever bring out of that office the reputation which carries him into it. The honeymoon would be as short in that case as in any other, and its moments of ecstasy would be ransomed by years of torment and hatred.”

“Ridicule is the only weapon which can be used against unintelligible propositions.”

“The whole art of government consists in the art of being honest.”

“That ideas should freely spread from one to another over the globe, for the moral and mutual instruction of man, and improvement of his condition, seems to have been peculiarly and benevolently designed by nature, when she made them, like fire, expansible over all space, without lessening their density in any point, and like the air in which we breathe, move, and have our physical being, incapable of confinement or exclusive appropriation. Inventions then cannot, in nature, be a subject of property.”

“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.” 

“Man once surrendering his reason, has no remaining guard against absurdities the most monstrous, and like a ship without rudder, is the sport of every wind. With such persons, gullibility, which they call faith, takes the helm from the hand of reason, and the mind becomes a wreck.”

“If a nation expects to be ignorant and free, in a state of civilization, it expects what never was and never will be.”

“the measure of society is how it treats the weakest members”