“Do not be too severe upon the errors of the people, but reclaim them by enlightening them.”

“I would rather be exposed to the inconveniences attending too much liberty, than those attending too small a degree of it.”

“The Christian god can easily be pictured as virtually the same god as the many ancient gods of past civilizations. The Christian god is a three headed monster cruel vengeful and capricious. If one wishes to know more of this raging three headed beast like god one only needs to look at the caliber of people who say they serve him. They are always of two classes fools and hypocrites. ”

“He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me. 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.”

“It is the duty of every American citizen to take part in a vigorous debate on the issues of the day.”

“History, in general, only informs us what bad government is.” 

“not to find out new principles, or new arguments, never before thought of . . . but to place before mankind the common sense of the subject, in terms so plain and firm as to command their assent, and to justify ourselves in the independent stand we are compelled to take.”

“Follow truth wherever it may lead you.”

“Freedom, the first-born of science.”

“The constitution of most of the states (and of the United States) assert that all power is inherent in the people; that they may exercise it by themselves; that it is their right and duty to be at all times armed and that they are entitled to freedom of person, freedom of religion, freedom of property, and freedom of the press.”

“I consider him [Alexander von Humboldt] the most important scientist whom I have met.”

“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.” 

“Enlighten the people generally, and tyranny and opressions of the body and mind will vanish like evil spirits at the dawn of day.”

“The dead should not rule the living.”

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