“Question with boldness even the existence of a God; because, if there be one, he must more approve of the homage of reason, than that of blind-folded fear.”

“[It is a] happy truth that man is capable of self-government, and only rendered otherwise by the moral degradation designedly superinduced on him by the wicked acts of his tyrant.”

“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.” 

“They (religions) dread the advance of science as witches do the approach of daylight and scowl on the fatal harbinger announcing the subversions of the duperies on which they live.”

“Any Government strong enough to give you what you want, is a Government strong enough to take everything you have!” 

“Tyranny is defined as that which is legal for the government but illegal for the citizenry.”

“While the art of printing is left to us science can never be retrograde; what is once acquired of real knowledge can never be lost.”

“If the present Congress errs in too much talking, how can it be otherwise in a body to which the people send 150. lawyers, whose trade it is to question everything, yield nothing, & talk by the hour? That 150. lawyers should do business together ought not to be expected. But to return again to our subject.” 

“Delay is preferable to error.”

“The policy of the American government is to leave its citizens free, neither restraining them nor aiding them in their pursuits.”

“The only security of all is in a free press.”

“Follow truth wherever it may lead you.”

“May I never get too busy in my own affairs that I fail to respond to the needs of others with kindness and compassion.”

“Perceiving the order of nature to be that individual happiness shall be inseparable from the practice of virtue, I am willing to hope it may have ordained that the fall of the wicked shall be the rise of the good.  To J. Correa de Serra, Monticello, Apr. 19, 1814”

“The art of life is the art of avoiding pain.”