Denis Diderot

"Go further, and require each of them to make a contribution: you will see how many things are still missing, and you will be obliged to get the assistance of a large number of men who belong to different classes, priceless men, but to whom the gates of the academies are nonetheless closed because of their social station. All the members of these learned societies are more than is needed for a single object of human science; all the societies together are not sufficient for a science of man in general."

"La puissance qui s'acquiert par la violence n'est qu'une usurpation, et ne dure qu'autant que la force de celui qui commande l'emporte sur celle de ceux qui obéissent."

"The good of the people must be the great purpose of government. By the laws of nature and of reason, the governors are invested with power to that end. And the greatest good of the people is liberty. It is to the state what health is to the individual."

"Reason is to the philosopher what grace is to the Christian. Grace causes the Christian to act, reason the philosopher. Other men are carried away by their passions, their actions not being preceded by reflection: these are the men who walk in darkness. On the other hand, the philosopher, even in his passions, acts only after reflection; he walks in the dark, but by a torch. The philosopher forms his principles from an infinity of particular observations. Most people adopt principles without thinking of the observations that have produced them, they believe the maxims exist, so to speak, by themselves. But the philosopher takes maxims from their source; he examines their origin; he knows their proper value, and he makes use of them only in so far as they suit him. Truth is not for the philosopher a mistress who corrupts his imagination and whom he believes to be found everywhere; he contents himself with being able to unravel it where he can perceive it. He does not confound it with probability; he takes for true what is true, for false what is false, for doubtful what is doubtful, and probable what is only probable. He does more, and here you have a great perfection of the philosopher: when he has no reason by which to judge, he knows how to live in suspension of judgment... The philosophical spirit is, then, a spirit of observation and exactness, which relates everything to true principles..."

"To say that man is a compound of strength and weakness, light and darkness, smallness and greatness, is not to indict him, it is to define him."

"Aucun homme n'a recu de la nature le droit de commander aux autres. La liberté est un présent du ciel, et chaque individu de la meme espèce a le droit d'en jouir aussitòt qu'il jouit de la raison."

"To prove the Gospels by a miracle is to prove an absurdity by something contrary to nature."

"This is a work that cannot be completed except by a society of men of letters and skilled workmen, each working separately on his own part, but all bound together solely by their zeal for the best interests of the human race and a feeling of mutual good will."

"We do not know nature; causes hidden in her breast might have produced everything. In your turn, observe the polyp of Trembley: does it not contain in itself the causes which bring about regeneration? Why then would it be absurd to think that there are physical causes by reason of which everything has been made, and to which the whole chain of this vast universe is so necessarily bound and held that, nothing which happens, could have failed to happen,—causes, of which we are so invincibly ignorant that we have had recourse to a God, who, as some aver, is not so much as a logical entity? Thus to destroy chance is not to prove the existence of a supreme being, since there may be some other thing which is neither chance nor God—I mean, nature. It follows that the study of nature can make only unbelievers; and the way of thinking of all its more successful investigators proves this."

"From fanaticism to barbarism is only one step."

"If you want me to believe in God, you must make me touch him."

"What is this world? A complex whole, subject to endless revolutions. All these revolutions show a continual tendency to destruction; a swift succession of beings who follow one another, press forward, and vanish; a fleeting symmetry; the order of a moment. I reproached you just now with estimating the perfection of things by your own capacity; and I might accuse you here of measuring its duration by the length of your own days. You judge of the continuous existence of the world, as an ephemeral insect might judge of yours. The world is eternal for you, as you are eternal to the being that lives but for one instant. Yet the insect is the more reasonable of the two. For what a prodigious succession of ephemeral generations attests your eternity! What an immeasurable tradition! Yet shall we all pass away, without the possibility of assigning either the real extension that we filled in space, or the precise time that we shall have endured. Time, matter, space — all, it may be, are no more than a point."

"As to all the outward signs that awaken within us feelings of sympathy and compassion, the blind are only affected by crying; I suspect them in general of lacking humanity. What difference is there for a blind man, between a man who is urinating, and man who, without crying out, is bleeding? And we ourselves, do we not cease to commiserate, when the distance or the smallness of the objects in question produce the same effect on us as the lack of sight produces in the blind man? All our virtues depend on the faculty of the senses, and on the degree to which external things affect us. Thus I do not doubt that, except for the fear of punishment, many people would not feel any remorse for killing a man from a distance at which he appeared no larger than a swallow. No more, at any rate, than they would for slaughtering a cow up close. If we feel compassion for a horse that suffers, but if we squash an ant without any scruple, isn’t the same principle at work?"

"When one compares the talents one has with those of a Leibniz, one is tempted to throw away one's books and go die quietly in the dark of some forgotten corner."

"Only a very bad theologian would confuse the certainty that follows revelation with the truths that are revealed. They are entirely different things."

"Il y a un peu de testicule au fond de nos sentiments les plus sublimes et de notre tendresse la plus épurée."

"There is no kind of harassment that a man may not inflict on a woman with impunity in civilized societies."

"Impenetrable in their dissimulation, cruel in their vengeance, tenacious in their purposes, unscrupulous as to their methods, animated by profound and hidden hatred for the tyranny of man — it is as though there exists among them an ever-present conspiracy toward domination, a sort of alliance like that subsisting among the priests of every country."

"The arbitrary rule of a just and enlightened prince is always bad. His virtues are the most dangerous and the surest form of seduction: they lull a people imperceptibly into the habit of loving, respecting, and serving his successor, whoever that successor may be, no matter how wicked or stupid."

"L'esprit de l'escalier"

"It has been said that love robs those who have it of their wit, and gives it to those who have none."

"Man was born to live with his fellow human beings. Separate him, isolate him, his character will go bad, a thousand ridiculous affects will invade his heart, extravagant thoughts will germinate in his brain, like thorns in an uncultivated land."

"As for our celebrated lawgivers, who have cast us in our present awkward mold, you may be sure that they have acted to serve their interests and not ours. Witness all our political, civil, and religious institutions — examine them thoroughly: unless I am very much mistaken, you will see how, through the ages, the human race has been broken to the halter that a handful of rascals were itching to impose. Watch out for the fellow who talks about putting things in order! Putting things in order always means getting other people under your control."

"The wisest among us is very lucky never to have met the woman, be she beautiful or ugly, intelligent or stupid, who could drive him crazy enough to be fit to be put into an asylum."

"How old the world is! I walk between two eternities... What is my fleeting existence in comparison with that decaying rock, that valley digging its channel ever deeper, that forest that is tottering and those great masses above my head about to fall? I see the marble of tombs crumbling into dust; and yet I don’t want to die!"

"I have often seen an actor laugh off the stage, but I don’t remember ever having seen one weep."

"Justice is the first virtue of those who command, and stops the complaints of those who obey."

"Et ses mains ourdiraient les entrailles du prêtre, Au défaut d’un cordon pour étrangler les rois."

"The more man ascends through the past, and the more he launches into the future, the greater he will be, and all these philosophers and ministers and truth-telling men who have fallen victims to the stupidity of nations, the atrocities of priests, the fury of tyrants, what consolation was left for them in death? This: That prejudice would pass, and that posterity would pour out the vial of ignominy upon their enemies. O Posterity! Holy and sacred stay of the unhappy and the oppressed; thou who art just, thou who art incorruptible, thou who findest the good man, who unmaskest the hypocrite, who breakest down the tyrant, may thy sure faith, thy consoling faith never, never abandon me!"

"Pithy sentences are like sharp nails which force truth upon our memory."

"The best doctor is the one you run for and can't find."

"[Africans are] always vicious... mostly inclined to lasciviousness, vengeance, theft and lies."

"Distance is a great promoter of admiration!"

"We are far more liable to catch the vices than the virtues of our associates."

"Evil always turns up in this world through some genius or other."

"There is no moral precept that does not have something inconvenient about it."

"I am beginning to feel that I am growing old; soon, I shall have to eat mush like children. I shall no longer be able to speak, which will be a rather great advantage for others and but a small inconvenience for myself.... The time in which I count in years is gone; that in which I count in days is here.... I had thought that the fibers of the heart would grow callous with age, it's not at all the case. I am not sure that my sensitivity hasn't increased; everything moves me, affects me.... To fade out between a man feeling your pulse and another bothering your head; not to know where one comes from, why one came, where one is going ..."

"I believe in God, although I live very happily with atheists... It is very important not to mistake hemlock for parsley; but not at all so to believe or not in God."

"There are things I can't force. I must adjust. There are times when the greatest change needed is a change of my viewpoint."

"Happiest are the people who give most happiness to others."

"[Jews are] angry and brutish people, vile and vulgar men, slaves worthy of the yoke [Talmudism] which you bear... Go, take back your books and remove yourselves from me. [ The Talmud ] taught the Jews to steal the goods of Christians, to regard them as savage beasts, to push them over the precipice... to kill them with impunity and to utter every morning the most horrible imprecations against them."

"When superstition is allowed to perform the task of old age in dulling the human temperament, we can say goodbye to all excellence in poetry, in painting, and in music."

"To attempt the destruction of our passions is the height of folly. What a noble aim is that of the zealot who tortures himself like a madman in order to desire nothing, love nothing, feel nothing, and who, if he succeeded, would end up a complete monster!"

"The God of the Christians is a father who makes much of his apples, and very little of his children."

"On doit exiger de moi que je cherche la vérité, mais non que je la trouve."

"There is no good father who would want to resemble our Heavenly Father"

"We are constantly railing against the passions; we ascribe to them all of man’s afflictions, and we forget that they are also the source of all his pleasures … But what provokes me is that only their adverse side is considered … and yet only passions, and great passions, can raise the soul to great things. Without them there is no sublimity, either in morals or in creativity. Art returns to infancy, and virtue becomes small-minded."

"Superstition is more injurious to God than atheism."

"Scepticism is the first step towards truth."

"The purpose of an encyclopedia is to collect knowledge disseminated around the globe; to set forth its general system to the men with whom we live, and transmit it to those who will come after us, so that the work of preceding centuries will not become useless to the centuries to come; and so that our offspring, becoming better instructed, will at the same time become more virtuous and happy, and that we should not die without having rendered a service to the human race in the future years to come"