We do not know nature; causes hidden in her breast might have produced — Denis Diderot

"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."

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

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

"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..."

"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, its not at all the case. I am not sure that my sensitivity hasnt 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 ..."

"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."

"One of the first major steps in the direction of modern skepticism came through the victory of Occam over Aquinas in a controversy about language. The statement that modi essendi were replaced by modi significandi et intelligendi, or that ontological referents were abandoned in favor of pragmatic significations, describes broadly the change in philosophy which continues to our time. From Occam to Bacon, from Bacon to Hobbes, and from Hobbes to contemporary semanticists, the progression is clear: ideas become psychological figments, words become useful signs. ... To one completely committed to this realm of becoming, as are the empiricists, the claim to apprehend verities is a sign of . Probably we have here but a highly sophisticated expression of the doctrine that ideals are hallucination and that the only normal, sane person is the healthy extrovert, making instant, instinctive adjustments to the stimuli of the material world."

"To have success in science, you need some luck. But to succeed in science, you need a lot more than luck. And its not enough to be smart — lots of people are very bright and get nowhere in life. In my view, you have to combine intelligence with a willingness not to follow conventions when they block your path forward."

"I, too, believed it was impossible to change the existing society into one that would be for the benefit of all; neither could I espouse any given ideal for society. But [...] I felt that even if one did not have an ideal vision of society, one could have one’s work to do. Whether it was successful or not was not our concern; it was enough that we believed it to be a valid work. The accomplishment of that work, I believed, was what our real life was about. Yes. I want to carry out a work of my own; for I feel that by so doing our lives are rooted in the here and now, not in some far-off ideal goal."

"We have already mentioned what may, perhaps, appear paradoxical to some of our readers, — that the division of labour can be applied with equal success to mental as to mechanical operations, and that it ensures in both the same economy of time."

"The war was finished. It had lasted ten equivalent years and taken ten million lives. Thus it was neither of long duration nor of serious attrition. It hadnt any great significance; it was not intended to have. It did not prove a point, since all points had long ago been proven. What it did, perhaps, was to emphasize an aspect, sharpen a concept, underline a trend. On the whole it was a successful operation. Economically and ecologically it was of healthy effect, and who should grumble? And after wars, men go home. No, no, men start for home. Its not the same."

"The final test of a leader is that he leaves behind him in other men the conviction and the will to carry on. ... The genius of a good leader is to leave behind him a situation which common sense, without the grace of genius, can deal with successfully."