“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.” 

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

“Reason and free inquiry are the only effectual agents against error.”

“He who permits himself to tell a lie once, finds it much easier to do it the second time.”

“I am not a Federalist because I never submitted the whole system of my opinions to the creed of any party of men whatever....Such an addiction is the last degradation of a free and moral agent. If I could not go to heaven but with a party, I would not go there at all.”

“Take things always by their smooth handle.”

“Orang yang membiarkan dirinya berbohong sekali, akan menyadari bahwa lebih mudah berbohong untuk kedua dan ketiga kali sampai menjadi kebiasaan.”

“I am not among those who fear the people. They, and not the rich, are our dependence for continued freedom.”

“he repudiated the writings of the Apostle Paul," whom he considered the (first corrupter of the doctrines of Jesus”

“A habilidade mais valiosa é aquela de jamais usar duas palavras quando uma apenas basta.”

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

“As you say of yourself, I too am an Epicurean. I consider the genuine (not the imputed) doctrines of Epicurus as containing everything rational in moral philosophy which Greece and Rome have left us.

“Never trouble another for what you can do yourself”

“He who knows nothing is closer to the truth than he whose mind is filled with falsehoods and errors.”

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