“...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 dead should not rule the living.”

“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 object most interesting to me for the residue of my life, will be to see you both developing daily those principles of virtue and goodness which will make you valuable to others and happy in yourselves, and acquiring those talents and that degree of science which will guard you at all times against ennui, the most dangerous poison of life. A mind always employed is always happy. This is the true secret, the grand recipe for felicity....In a world which furnishes so many employments which are useful, and so many which are amusing, it is our own fault if we ever know what ennui is...”

“The glow of one warm thought is to me worth more than money”

“The opinions and beliefs of men follow involuntarily the evidence proposed to their minds.”

“If there is one principle more deeply rooted in the mind of every American, it is that we should have nothing to do with conquest.”

“History, by apprising [the people] of the past, will enable them to judge of the future.” 

“I believe that every human mind feels pleasure in doing good to another.”

“You have heard of the new chemical nomenclature endeavored to be introduced by Lavoisier, Fourcroy, &c. Other chemists of this country, of equal note, reject it, and prove in my opinion that it is premature, insufficient and false. These latter are joined by the British chemists; and upon the whole, I think the new nomenclature will be rejected, after doing more harm than good. There are some good publications in it, which must be translated into the ordinary chemical language before they will be useful.”

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

“Half a loaf is better than no bread” 

“The man who reads nothing at all is better educated than the man who reads nothing but newspapers.”

“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.”

“When the clergy addressed General Washington on his departure from the government, it was observed in their consultation that he had never on any occasion said a word to the public which showed a belief in the Christian religion and they thought they should so pen their address as to force him at length to declare publicly whether he was a Christian or not. They did so. However [Dr. Rush] observed the old fox was too cunning for them. He answered every article of their address particularly except that, which he passed over without notice... I know that Gouverneur Morris, who pretended to be in his secrets & believed himself to be so, has often told me that General Washington believed no more of that system than he himself did.