“...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.”

“The clause too, reprobating the enslaving the inhabitants of Africa, was struck out in complaisance to South Carolina and Georgia, who had never attempted to restrain the importation of slaves, and who on the contrary still wished to continue it. Our northern brethren also I believe felt a little tender under those censures; for tho' their people have very few slaves themselves yet they had been pretty considerable carriers of them to others.”

“A coward is much more exposed to quarrels than a man of spirit.”

“I predict future happiness for Americans if they can prevent the government from wasting the labors of the people under the pretense of taking care of them.

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

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

“History, I believe, furnishes no example of a priest-ridden people maintaining a free civil government. This marks the lowest grade of ignorance of which their civil as well as religious leaders will always avail themselves for their own purposes.”

“The whole art of government consists in the art of being honest. Only aim to do your duty, and mankind will give you credit where you fail.”

“Kalau marah, berhitunglah sampai sepuluh sebelum berbicara, atau bahkan seratus kalau sedang marah sekali.” 

“I had rather be shut up in a very modest cottage with my books, my family and a few old friends, dining on simple bacon, and letting the world roll on as it liked, than to occupy the most splendid post, which any human power can give.”

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

“The principle of spending money to be paid by posterity, under the name of funding, is but swindling futurity on a large scale.”

“I'm a greater believer in luck, and I find the harder I work the more I have of it”

“No people who are ignorant can be truly free.”

“Some are whigs, liberals, democrats, call them what you please. Others are tories, serviles, aristocrats, &c. The latter fear the people, and wish to transfer all power to the higher classes of society; the former consider the people as the safest depository of power in the last resort; they cherish them therefore, and wish to leave in them all the powers to the exercise of which they are competent.”