“While the art of printing is left to us science can never be retrograde; what is once acquired of real knowledge can never be lost.”

“...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.”

“[n regard to Jesus believing himself inspired] This belief carried no more personal imputation than the belief of Socrates that he was under the care and admonition of a guardian demon. And how many of our wisest men still believe in the reality of these inspirations while perfectly sane on all other subjects (Works, Vol. iv, p. 327).”

“The fantastical idea of virtue and the public good being a sufficient security to the state against the commission of crimes...was never mine. It is only the sanguinary hue of our penal laws which I meant to object to. Punishments I know are necessary, and I would provide them strict and inflexible, but proportioned to the crime. Death might be inflicted for murder and perhaps for treason, [but I] would take out of the description of treason all crimes which are not such in their nature. Rape, buggery, etc., punish by castration. All other crimes by working on high roads, rivers, gallies, etc., a certain time proportioned to the offence... Laws thus proportionate and mild should never be dispensed with. Let mercy be the character of the lawgiver, but let the judge be a mere machine. The mercies of the law will be dispensed equally and impartially to every description of men; those of the judge or of the executive power will be the eccentric impulses of whimsical, capricious designing man.”

“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.

“As new discoveries are made, new truths discovered and manners and opinions change with the change of circumstances, institutions must advance also to keep pace with the times.”

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

“The equal rights of man, and the happiness of every individual, are now acknowledged to be the only legitimate objects of government.”

“The greatest service which can be rendered any country is to add a useful plant to its culture.

“The people cannot be all, and always, well informed. The part which is wrong will be discontented, in proportion to the importance of the facts they misconceive. If they remain quiet under such misconceptions, it is lethargy, the forerunner of death to the public liberty. ... What country before ever existed a century and half without a rebellion? And what country can preserve its liberties if their rulers are not warned from time to time that their people preserve the spirit of resistance? Let them take arms. The remedy is to set them right as to facts, pardon and pacify them. What signify a few lives lost in a century or two? The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants. It is its natural manure.”

“Let us save what remains: not by vaults and locks which fence them from the public eye and use in consigning them to the waste of time, but by such a multiplication of copies, as shall place them beyond the reach of accident.”

“The natural progress of things is for liberty to yield, and government to gain ground.”

“War is an instrument entirely inefficient toward redressing wrong; and multiplies, instead of indemnifying losses.”

“I find friendship to be like wine, raw when new, ripened with age, the true old man's milk and restorative cordial.”