Since labour is motion, time is its natural measure.

Roemer used eclipses of the satellites of Jupiter, and sought how much the event fell behind its prediction. But... this prediction is made... by... astronomic laws; for instance Newton's... The velocity of light... is adopted, such that the astronomic laws compatible with this value may be as simple as possible.

The ideal of strictly scientific method in mathematics which I have tried to realise here, and which perhaps might be named after Euclid I should like to describe in the following way... The novelty of this book does not lie in the content of the theorems but in the development of the proofs and the foundations on which they are based... With this book I accomplish an object which I had in view in my Begriffsschrift of 1879 and which I announced in my Grundlagen der Arithmetik. I am here trying to prove the opinion on the concept of number that I expressed in the book last mentioned.

And see, a kind, refined lady will devour the carcasses of these animals with full assurance that she is doing right, at the same time asserting two contradictory propositions: First, that she is, as her doctor assures her, so delicate that she cannot be sustained by vegetable food alone, and that for her feeble organism flesh is indispensable; and, secondly, that she is so sensitive that she is unable, not only herself to inflict suffering on animals, but even to bear the sight of suffering. Whereas the poor lady is weak precisely because she has been taught to live upon food unnatural to man; and she cannot avoid causing suffering to animals - for she eats them.

Tis the sharpness of our mind that gives the edge to our pains and pleasures.

Long before physics or psychology were born, pain disintegrated matter, and affliction the soul.

All things as subsist from nature appear to contain in themselves a principle of motion and permanency; some according to place, others according to increase and diminuation; and others according to change in quality. 

The philosopher will ask himself ... if the criticism we are now suggesting is not the philosophy which presses to the limit that criticism of false gods which Christianity has introduced into our history.

Pretend what we may, the whole man within us is at work when we form our philosophical opinions. Intellect, will, taste, and passion co-operate just as they do in practical affairs; and lucky it is if the passion be not something as petty as a love of personal conquest over the philosopher across the way.

The historical approach, with its aim of detecting how things began and arriving from these origins at a knowledge of their nature, is certainly perfectly legitimate; but it also has its limitations. If everything were in continual flux, and nothing maintained itself fixed for all time, there would no longer be any possibility of getting to know about the world, and everything would be plunged into confusion.

Gentlemen, the melancholy event of yesterday reads to us an awful lesson against being too much troubled about any of the objects of ordinary ambition. The worthy gentleman, who has been snatched from us at the moment of the election, and in the middle of contest, whilst his desires were as warm, and his hopes as eager as ours, has feelingly told us, what shadows we are, and what shadows we pursue.

Existentialism is nothing else but an attempt to draw the full conclusions from a consistently atheistic position. Its intention is not in the least that of plunging men into despair. And if by despair one means as the Christians do - any attitude of unbelief, the despair of the existentialists is something different. Existentialism is not atheist in the sense that it would exhaust itself in demonstrations of the non-existence of God. It declares, rather, that even if God existed that would make no difference from its point of view. Not that we believe God does exist, but we think that the real problem is not that of His existence; what man needs is to find himself again and to understand that nothing can save him from himself, not even a valid proof of the existence of God. In this sense existentialism is optimistic. It is a doctrine of action, and it is only by self-deception, by confining their own despair with ours that Christians can describe us as without hope.

The compassionate are not rich; therefore, the rich are not compassionate.

Hegel made famous his aphorism that all the rational is real and all the real rational; but there are many of us who, unconvinced by Hegel, continue to believe that the real, the really real, is irrational, that reason builds upon irrationalities. Hegel, a great framer of definitions, attempted with definitions to reconstruct the universe, like that artillery sergeant who said that cannon were made by taking a hole and enclosing it with steel.

Let us greedily enjoy our friends, because we do not know how long this privilege will be ours.

All religions promise a reward for excellences of the will or heart, but none for excellences of the head or understanding.

The Few assume to be the deputies, but they are often only the despoilers of the Many.

Egos appear by setting themselves apart from other egos.

There's a bit of testicle at the bottom of our most sublime feelings and our purest tenderness.

There is philosophy, which is about conceptual analysis - about the meaning of what we say - and there is all of this ... all of life.

All science must start with some assumptions as to the ultimate analysis of the facts with which it deals. These assumptions are justified partly by their adherence to the types of occurrence of which we are directly conscious, and partly by their success in representing the observed facts with a certain generality, devoid of ad hoc suppositions.

The ones who are preoccupied by logic are above all; to read their works, one is tempted to believe they have advanced only step by step, after the manner of a Vauban who pushes on his trenches against the place besieged, leaving nothing to chance. The others are guided by intuition and, at the first stroke, make quick but sometimes precarious conquests, like bold cavalrymen of the advance guard.

Mathematics is as little a natural science as philosophy is one of the humanities. Philosophy in its essence belongs as little in the philosophical faculty as mathematics belongs to natural science. To house philosophy and mathematics in this way today seems to be a blemish or a mistake in the catalog of the universities. Plato put over the entrance to his Academy the words: "Let no one who has not grasped the mathematical enter here!"

Whoever blasphemes against the Father will be forgiven, and whoever blasphemes against the Son will be forgiven, but whoever blasphemes against the Holy Spirit will not be forgiven either on earth or in heaven.

I am NOT nothing! A vaporous phosphorescence on a damp meadow, a miserable worm that crawls and loves, that shouts and talks about wings for an hour or two until his mouth is blocked with earth. The dark powers give no other answer. But within me a deathless Cry, superior to me, continues to shout. For whether I want to or not, I am also, without doubt, a part of the visible and the invisible Universe. We are one.

Instead of deciding once in three or six years which member of the ruling class was to misrepresent the people in Parliament, universal suffrage was to serve the people, constituted in Communes, as individual suffrage serves every other employer in the search for the workmen and managers in his business.

There never, gentlemen, was a period in which the steadfastness of some men has been nut to so sore a trial. It is not very difficult for well-formed minds to abandon their interest; but the separation of fame and virtue is an harsh divorce. Liberty is in danger of being made unpopular to Englishmen. Contending for an imaginary power, we begin to acquire the spirit of domination, and to lose the relish of honest equality.

Sex-appeal is the keynote of our whole civilization.

I have no idea of a liberty unconnected with honesty and justice. Nor do I believe, that any good constitutions of government, or of freedom, can find it necessary for their security to doom any part of the people to a permanent slavery. Such a constitution of freedom, if such can be, is in effect no more than another name for the tyranny of the strongest faction; and factions in republics have been, and are, full as capable as monarchs, of the most cruel oppression and injustice.

The successful revolutionary is a statesman, the unsuccessful one a criminal.

In contemplating thyself never include the vessel which surrounds thee, and these instruments which are attached about it. For they are like an ax, differing only in this, that they grow to the body. For indeed there is no more use in these parts without the cause which moves and checks them than in the weaver's shuttle, and the writer's pen, and the driver's whip.

Things have their root and their branches. Affairs have their end and their beginning. To know what is first and what is last will lead near to what is taught in the Great Learning.

All our knowledge falls with the bounds of experience.

The real struggle is not between East and West, or capitalism and communism, but between education and propaganda.

What matters the party to me? I shall find enough anyhow who unite with me without swearing allegiance to my flag.

The next day as they were leaving Bethany, Jesus was hungry. Seeing in the distance a fig tree in leaf, he went to find out if it had any fruit. When he reached it, he found nothing but leaves, because it was not the season for figs. Then he said to the tree, “May no one ever eat fruit from you again.” And his disciples heard him say it. The next day when they came out from Bethany, He was hungry. After seeing in the distance a fig tree with leaves, He went to find out if there was anything on it. When He came to it, He found nothing but leaves, because it was not the season for figs. He said to it, "May no one ever eat fruit from you again!"

It would be some consolation for the feebleness of ourselves and our works, if all things should perish as slowly as they come into being; but as it is, increases are of sluggish growth, but the way to ruin is rapid.

Christianity has functioned for the normative self-understanding of modernity as more than a mere precursor or a catalyst. Egalitarian universalism, from which sprang the ideas of freedom and social solidarity, of an antonomous conduct of life and emancipation, of the individual morality of conscience, human rights, and democracy, is the direct heir to the judaic ethic of justice and the Christian ethic of love. This legacy, substantially unchanged, has been the object of continual critical appropriation and reinterpretation. To this day, there is no alternative to it. And in the light of the current challenges of a postnational constellation, we continue to draw on the substance of this heritage. Everything else is just idle postmodern talk.

Wonderful is the depth of Thy oracles, whose surface is before us, inviting the little ones; and yet wonderful is the depth, O my God, wonderful is the depth. It is awe to look into it; and awe of honour, and a tremor of love. The enemies thereof I hate vehemently. Oh, if Thou wouldest slay them with Thy two-edged sword, that they be not its enemies! For thus do I love, that they should be slain unto themselves that they may live unto Thee.

Cities are, first of all, seats of the highest economic division of labor. They produce thereby such extreme phenomena as in Paris the remunerative occupation of the quatorzième. They are persons who identify themselves by signs on their residences and who are ready at the dinner hour in correct attire, so that they can be quickly called upon if a dinner party should consist of thirteen persons. In the measure of its expansion, the city offers more and more the decisive conditions of the division of labor. It offers a circle which through its size can absorb a highly diverse variety of services.

At the deepest level, the desire for complete union with God exhibits a narcissistic structure.

There is no such thing as data-driven thinking.

I do not think it can be questioned that sympathy is a genuine motive, and that some people at some times are made somewhat uncomfortable by the sufferings of some other people. It is sympathy that has produced the many humanitarian advances of the last hundred years. We are shocked when we hear stories of the ill-treatment of lunatics, and there are now quite a number of asylums in which they are not ill-treated. Prisoners in Western countries are not supposed to be tortured, and when they are, there is an outcry if the facts are discovered. We do not approve of treating orphans as they are treated in Oliver Twist.

You have just dined, and however scrupulously the slaughterhouse is concealed in the graceful distance of miles, there is complicity.

The sure conviction that we could if we wanted to is the reason so many good minds are idle.

I suppose I must be out of sorts to feel everything so deeply. Sometimes, however, it seems to me that i am not really a human being at all, but like a bird or a beast in human form. I feel so much more at home even in a scrap of garden like the one here, and still more in the meadows when the grass is humming with bees than - at one of the our party congresses.

If our intention now is to reveal classical unreason on its own terms, outside of its ties with dreams and error, it must be understood not as a form of reason that is somehow diseased, lost or mad, but quite simply as reason dazzled.

Mathematical and physiological researches have shown that the space of experience is simply an actual case of many conceivable cases, about whose peculiar properties experience alone can instruct us.