“I know no safe depository of the ultimate powers of the society but the people themselves ; and if we think them not enlightened enough to exercise their control with a wholesome discretion, the remedy is not to take it from them, but to inform their discretion by education. This is the true corrective of abuses of constitutional power.” 

“To compel a man to subsidize with his taxes the propagation of ideas which he disbelieves and abhors is sinful and tyrannical.”

“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 satisfied, and sufficiently occupied with the things which are, without tormenting or troubling myself about those which may indeed be, but of which I have no evidence.”

“I predict future happiness for Americans, if they can prevent the government from wasting the labors of the people under the pretense of taking care of them.” 

“On every question of construction (of the Constitution) let us carry ourselves back to the time when the Constitution was adopted, recollect the spirit of the debates, and instead of trying what meaning may be squeezed out of the text, or invented against it, conform to the probable one in which it was passed.”

“Experience demands that man is the only animal which devours his own kind, for I can apply no milder term to the general prey of the rich on the poor.”

“I have examined all the known superstitions of the world,and I do not find in our particular superstition of Christianity one redeeming feature. They are all alike founded on fables and mythology. Millions of innocent men women and children since the introduction of Christianity,have been burnt, tortured, fined and imprisoned. What has been the effect of this coercion? To make one half the world fools and the other half hypocrites; to support roguery and error all over the earth.”

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

“When injustice becomes law, resistance becomes duty.”

“The most valuable of all talents is that of never using two words when one will do.”

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

“The pretense that the workings of the mind, like the actions of the body, are subject to the control of laws, does not seem sufficiently demolished. ... The legitimate powers of government extend to such acts only as are injurious to others.”

“Whenever the people are well-informed, they can be trusted with their own government”

“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.”