The ontological concept of truth is in the centre of a logic which may serve as a model of pre- technological rationality. It is the rationality of a two-dimensional universe of discourse which, contrasts with the of thought and behavior that develop in the execution of the technological project.

The apparatus defeats its own purpose if its purpose is to create a humane existence on the basis of a humanized nature.

The happy consciousness is shaky enough-a thin surface over fear, frustration, and disgust.

Many, and I think the determining, constitutive facts remain outside the reach of the operational concept. And by virtue of this limitation-this methodological injunction against transitive concepts which might show the facts in their true light and call them by their true name-the descriptive analysis of the facts blocks the apprehension of facts and becomes an element of the ideology that sustains the facts. Proclaiming the existing social reality as its own norm, this sociology fortifies in the individuals the "faithless faith" in the reality whose victims they are.

Marx explains the alienation of labor as exemplified in, first, the relation of the worker to the product of his labor and, second, the relation of the worker to his own activity. P. 276

People talk, indeed, of a "primitive mentality", as, for example, to-day that of the inferior races, and in days gone by that of humanity in general, at whose door the responsibility for superstition should be laid.

The prestige of the Nobel Prize is due to many causes, but in particular to its twofold idealistic and international character: idealistic in that it has been designed for works of lofty inspiration; international in that it is awarded after the production of different countries has been minutely studied and the intellectual balance sheet of the whole world has been drawn up. Free from all other considerations and ignoring any but intellectual values, the judges have deliberately taken their place in what the philosophers have called a community of the mind.

Religion is to mysticism what popularization is to science. What the mystic finds waiting for him, then, is a humanity which has been prepared to listen to his message by other mystics invisible and present in the religion which is actually taught. Indeed his mysticism itself is imbued with this religion, for such was its starting point. His theology will generally conform to that of the theologians. His intelligence and his imagination will use the teachings of the theologians to express in words what he experiences, and in material images what he sees spiritually. And this he can do easily, since theology has tapped that very current whose source is the mystical. Thus his mysticism is served by religion, against the day when religion becomes enriched by his mysticism. This explains the primary mission which he feels to be entrusted to him, that of an intensifier of religious faith.

I would say act like a man of thought and think like a man of action.

The open society is one that is deemed in principle to embrace all humanity.

Intuition is a method of feeling one's way intellectually into the inner heart of a thing to locate what is unique and inexpressible in it.

I cannot escape the objection that there is no state of mind, however simple, that does not change every moment.

Sex-appeal is the keynote of our whole civilization.

The remembrance of forbidden fruit is the earliest thing in the memory of each of us, as it is in that of mankind.

The present contains nothing more than the past, and what is found in the effect was already in the cause.

Men do not sufficiently realise that their future is in their own hands. Theirs is the task of determining first of all whether they want to go on living or not. Theirs is the responsibility, then, for deciding if they want merely to live, or intend to make just the extra effort required for fulfilling, even on their refractory planet, the essential function of the universe, which is a machine for the making of gods.

Why did we obey? The question hardly occurred to us. We had formed the habit of deferring to our parents and teachers. All the same we knew very well that it was because they were our parents, because they were our teachers. Therefore, in our eyes, their authority came less from themselves than from their status in relation to us.

All the living hold together, and all yield to the same tremendous push. The animal takes its stand on the plant, man bestrides animality, and the whole of humanity, in space and in time, is one immense army galloping beside and before and behind each of us in an overwhelming charge able to beat down every resistance and clear the most formidable obstacles, perhaps even death.

The eyes see only what the mind is prepared to comprehend.

The spectacle of what religions have been in the past, of what certain religions still are to-day, is indeed humiliating for human intelligence. What a farrago of error and folly!'

A philosopher worthy of the name has never said more than a single thing: and even then it is something he has tried to say, rather than actually said. And he has said only one thing because he has seen only one point: and at that it was not so much a vision as a contact...

We suppose, it would seem, that concepts grow in the individual mind like leaves on a tree, and we think to discover their nature by studying their growth; we seek to define them psychologically, in terms of the human mind. But this account makes everything subjective, and if we follow it through to the end, does away with truth. What is known as the history of concepts is really a history either of our knowledge of concepts or of the meanings of words.

Without some affinity in human ideas art would certainly be impossible; but it can never be exactly determined how far the intentions of the poet are realized.

I hope I may claim in the present work to have made it probable that the laws of arithmetic are analytic judgments and consequently a priori. Arithmetic thus becomes simply a development of logic, and every proposition of arithmetic a law of logic, albeit a derivative one. To apply arithmetic in the physical sciences is to bring logic to bear on observed facts; calculation becomes deduction.

Often it is only after immense intellectual effort, which may have continued over centuries, that humanity at last succeeds in achieving knowledge of a concept in its pure form, by stripping off the irrelevant accretions which veil it from the eye of the mind.

Being true is different from being taken as true, whether by one or by many or everybody, and in no case is it to be reduced to it. There is no contradiction in something's being true which everybody takes to be false. I understand by 'laws of logic' not psychological laws of takings-to-be-true, but laws of truth. ...If being true is thus independent of being acknowledged by somebody or other, then the laws of truth are not psychological laws: they are boundary stones set in an eternal foundation, which our thought can overflow, but never displace. It is because of this that they have authority for our thought if it would attain truth. They do not bear the relation to thought that the laws of grammar bear to language; they do not make explicit the nature of our human thinking and change as it changes.

Facts, facts, facts,' cries the scientist if he wants to emphasize the necessity of a firm foundation for science. What is a fact? A fact is a thought that is true. But the scientist will surely not recognize something which depends on men's varying states of mind to be the firm foundation of science.

Gottlob Frege created modern logic including "for all," "there exists," and rules of proof. Leibniz and Boole had dealt only with what we now call "propositional logic" (that is, no "for all" or "there exists"). They also did not concern themselves with rules of proof, since their aim was to reach truth by pure calculation with symbols for the propositions. Frege took the opposite track: instead of trying to reduce logic to calculation, he tried to reduce mathematics to logic, including the concept of number.

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.

It really is worth the trouble to invent a new symbol if we can thus remove not a few logical difficulties and ensure the rigour of the proofs. But many mathematicians seem to have so little feeling for logical purity and accuracy that they will use a word to mean three or four different things, sooner than make the frightful decision to invent a new word.

A scientist can hardly meet with anything more undesirable than to have the foundations give way just as the work is finished. I was put in this position by a letter from Mr. Bertrand Russell when the work was nearly through the press.

If I compare arithmetic with a tree that unfolds upward into a multitude of techniques and theorems while its root drives into the depths, then it seems to me that the impetus of the root.

Is it always permissible to speak of the extension of a concept, of a class? And if not, how do we recognize the exceptional cases? Can we always infer from the extension of one concept's coinciding with that of a second, that every object which falls under the first concept also falls under the second?

Every good mathematician is at least half a philosopher, and every good philosopher is at least half a mathematician.

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.

A judgment, for me is not the mere grasping of a thought, but the admission of its truth.

If the task of philosophy is to break the domination of words over the human mind, then my concept notation, being developed for these purposes, can be a useful instrument for philosophers. I believe the cause of logic has been advanced already by the invention of this concept notation.

They [the wise spirits of antiquity in the first circle of Dante's Inferno] are condemned, Dante tells us, to no other penalty than to live in desire without hope, a fate appropriate to noble souls with a clear vision of life.

Skepticism, like chastity, should not be relinquished too readily.

I leave you but the sound of many a word In mocking echoes haply overheard, I sang to heaven. My exile made me free,from world to world, from all worlds carried me.

O world, thou choosest not the better part! It is not wisdom to be only wise, And on the inward vision close the eyes, But it is wisdom to believe the heart. Columbus found a world, and had no chart, Save one that faith deciphered in the skies; To trust the soul's invincible surmise Was all his science and his only art.

The idea of Christ is much older than Christianity.

In the Gospels, for instance, we sometimes find the kingdom of heaven illustrated by principles drawn from observation of this world rather than from an ideal conception of justice; ... They remind us that the God we are seeking is present and active, that he is the living God; they are doubtless necessary if we are to keep religion from passing into a mere idealism and God into the vanishing point of our thought and endeavour.

A child educated only at school is an uneducated child.

Although a poem be not made by counting of syllables upon the fingers, yet "numbers" is the most poetical synonym we have for verse, and "measure" the most significant equivalent for beauty, for goodness, and perhaps even for truth. Those early and profound philosophers, the followers of Pythagoras, saw the essence of all things in number, and it was by weight, measure, and number, as we read in the Bible, that the Creator first brought Nature out of the void.

Religions are not true or false, but better or worse.

There is nothing impossible in the existence of the supernatural: its existence seems to me decidedly probable.

Everything ideal has a natural basis and everything natural an ideal development.

No system would have ever been framed if people had been simply interested in knowing what is true, whatever it may be. What produces systems is the interest in maintaining against all comers that some favourite or inherited idea of ours is sufficient and right.

All living souls welcome whatsoever they are ready to cope with; all else they ignore, or pronounce to be monstrous and wrong, or deny to be possible.