“Of all machines, the human heart is the most complicated and inexplicable.”

“...never [enter] into dispute or argument with another. I never saw an instance of one of two disputants convincing the other by argument. I have seen many, on their getting warm, becoming rude, & shooting one another. ... When I hear another express an opinion which is not mine, I say to myself, he has a right to his opinion, as I to mine; why should I question it? His error does me no injury, and shall I become a Don Quixote, to bring all men by force of argument to one opinion? ... There are two classes of disputants most frequently to be met with among us. The first is of young students, just entered the threshold of science, with a first view of its outlines, not yet filled up with the details & modifications which a further progress would bring to their knoledge. The other consists of the ill-tempered & rude men in society, who have taken up a passion for politics. ... Consider yourself, when with them, as among the patients of Bedlam, needing medical more than moral counsel. Be a listener only, keep within yourself, and endeavor to establish with yourself the habit of silence, especially on politics. In the fevered state of our country, no good can ever result from any attempt to set one of these fiery zealots to rights, either in fact or principle. They are determined as to the facts they will believe, and the opinions on which they will act. Get by them, therefore, as you would by an angry bull; it is not for a man of sense to dispute the road with such an animal.”

“That liberty [is pure] which is to go to all, and not to the few or the rich alone. (to Horatio Gates, 1798)”

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

“The God who gave us life gave us liberty at the same time; the hand of force may destroy but cannot disjoin them.”

“I think one travels more usefully when they travel alone, because they reflect more."

“I cannot live without books: but fewer will suffice where amusement, and not use, is the only future object.” 

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

“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.”

“I have no ambition to govern men; it is a painful and thankless office.” 

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

“If you want something you’ve never had, you’ve got to do something you’ve never done before.”

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

“Our liberty depends on the freedom of the press, and that cannot be limited without being lost.”

“He who knows best knows how little he knows.”