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

“Peace, commerce, and honest friendship with all nations...entangling alliances with none”

“We hold these truths to be self-evident, that all men are created equal, that they are endowed, by their Creator, with certain unalienable Rights, that among these are Life, Liberty, and the pursuit of Happiness. That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or abolish it, and to institute new Government, laying its foundation on such principles, and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness. Prudence, indeed, will dictate that Governments long established should not be changed for light and transient causes; and accordingly all experience hath shewn, that mankind are more disposed to suffer, while evils are sufferable, than to right themselves by abolishing the forms to which they are accustomed. But when a long train of abuses and usurpations, pursuing invariably the same Object, evinces a design to reduce them under absolute Despotism, it is their right, it is their duty, to throw off such Government, and to provide new Guards for their future security.”

“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. Inventions then cannot, in nature, be a subject of property.”

“A nation which expects to be ignorant and free, in a state of civilization, expects that which never was and never will be.”

“Commerce with all nations, alliance with none, should be our motto.”

“I agree with yours of the 22d that a professorship of Theology should have no place in our institution. but we cannot always do what is absolutely best. those with whom we act, entertaining different views, have the power and the right of carrying them into practice. truth advances, & error recedes step by step only; and to do to our fellow-men the most good in our power, we must lead where we can, follow where we cannot, and still go with them, watching always the favorable moment for helping them to another step.

“It is reasonable that everyone who asks justice should do justice” 

“...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.”

“Equal and exact justice to all men, of whatever state or persuasion.”

“Freedom, the first-born of science.”

“A little patience, and we shall see the reign of witches pass over, their spells dissolve, and the people, recovering their true sight, restore their government to its true principles. It is true that in the meantime we are suffering deeply in spirit, and incurring the horrors of a war and long oppressions of enormous public debt...If the game runs sometime against us at home, we must have patience till luck turns, and then we shall have an opportunity of winning back the principles we have lost, for this is a game where principles are at stake.” 

“He has erected a multitude of New Offices, and sent hither swarms of Officers to harass our People, and eat out their substance.”

“A little rebellion now and then is a good thing.”

“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.”