Tractatus Logico-Philosophicus quotes

The book deals with the problems of philosophy and shows, as I believe, that the method of formulating these problems rests on the misunderstanding of the logic of our language. Its whole meaning could be summed up somewhat as follows:

What can be said at all can be said clearly; and whereof one cannot speak thereof one must be silent.

The book will, therefore, draw a limit to thinking, or rather—not to thinking, but to the expression of thoughts;

The world is everything that is the case.

The world is the totality of facts, not of things.

The world is everything that is the case.

The world is the totality of facts, not of things.

The world is determined by the facts, and by these being all the facts.

The thought contains the possibility of the state of affairs which it thinks. What is thinkable is also possible.

We cannot think anything unlogical, for otherwise we should have to think unlogically.

It used to be said that God could create everything, except what was contrary to the laws of logic. The truth is, we could not say of an “unlogical” world how it would look.

Colloquial language is a part of the human organism and is not less complicated than it. From it it is humanly impossible to gather immediately the logic of language.

Language disguises the thought; so that from the external form of the clothes one cannot infer the form of the thought they clothe, because the external form of the clothes is constructed with quite another object than to let the form of the body be recognized.

The silent adjustments to understand colloquial language are enormously complicated.

The silent adjustments to understand colloquial language are enormously complicated.

Most propositions and questions, that have been written about philosophical matters, are not false, but senseless.

We cannot, therefore, answer questions of this kind at all, but only state their senselessness. Most questions and propositions of the philosophers result from the fact that we do not understand the logic of our language.

Most questions and propositions of the philosophers result from the fact that we do not understand the logic of our language. (They are of the same kind as the question whether the Good is more or less identical than the Beautiful.)

And so it is not to be wondered at that the deepest problems are really no problems.

All philosophy is “Critique of language” (but not at all in Mauthner’s sense). Russell’s merit is to have shown that the apparent logical form of the proposition need not be its real form.

The object of philosophy is the logical clarification of thoughts. Philosophy is not a theory but an activity. A philosophical work consists essentially of elucidations. The result of philosophy is not a number of “philosophical propositions,” but to make propositions clear.

Philosophy should make clear and delimit sharply the thoughts which otherwise are, as it were, opaque and blurred.

Psychology is no nearer related to philosophy, than is any other natural science. The theory of knowledge is the philosophy of psychology.

It will mean the unspeakable by clearly displaying the speakable.

Everything that can be thought at all can be thought clearly. Everything that can be said can be said clearly.

Propositions can represent the whole reality, but they cannot represent what they must have in common with reality in order to be able to represent it—the logical form.

Thus a proposition “f⁡a” shows that in its sense the object a occurs, two propositions “f⁡a” and “g⁡a” that they are both about the same object. If two propositions contradict one another, this is shown by their structure; similarly if one follows from another, etc.

What can be shown cannot be said.

Now we understand our feeling that we are in possession of the right logical conception, if only all is right in our symbolism.

The tautology has no truth-conditions, for it is unconditionally true; and the contradiction is on no condition true. Tautology and contradiction are without sense. (Like the point from which two arrows go out in opposite directions.)

(I know, e.g. nothing about the weather, when I know that it rains or does not rain.)

Tautology and contradiction are, however, not nonsensical; they are part of the symbolism, in the same way that “0” is part of the symbolism of Arithmetic.

There is no causal nexus which justifies such an inference.

The events of the future cannot be inferred from those of the present.

Superstition is the belief in the causal nexus.

The events of the future cannot be inferred from those of the present. Superstition is the belief in the causal nexus.

The freedom of the will consists in the fact that future actions cannot be known now.

We could only know them if causality were an inner necessity, like that of logical deduction.—The connection of knowledge and what is known is that of logical necessity. (“A knows that p is the case” is senseless if p is a tautology.)

Contradiction is something shared by propositions, which no proposition has in common with another. Tautology is that which is shared by all propositions, which have nothing in common with one another. Contradiction vanishes so to speak outside, tautology inside all propositions.

Contradiction is the external limit of the propositions, tautology their substanceless centre.

If Tr is the number of the truth-grounds of the proposition “r”, Trs the number of those truth-grounds of the proposition “s” which are at the same time truth-grounds of “r”, then we call the ratio Trs:Tr the measure of the probability which the proposition …

The description of the most general propositional form is the description of the one and only general primitive sign in logic.

Logic must take care of itself.

A possible sign must also be able to signify. Everything which is possible in logic is also permitted. (“Socrates is identical” means nothing because there is no property which is called “identical.”

Russell’s definition of “=” won’t do; because according to it one cannot say that two objects have all their properties in common. (Even if this proposition is never true, it is nevertheless significant.)

Roughly speaking: to say of two things that they are identical is nonsense, and to say of one thing that it is identical with itself is to say nothing.

I write therefore not “f⁡(a,b).a=b” but “f⁡(aa)” (or “f⁡(bb)”). And not “f⁡(a,b).~a=b”, but “f⁡(a,b)”.

If I cannot give elementary propositions a priori then it must lead to obvious nonsense to try to give them.

The limits of my language mean the limits of my world.

Logic fills the world: the limits of the world are also its limits. We cannot therefore say in logic: This and this there is in the world, that there is not.

In fact what solipsism means, is quite correct, only it cannot be said, but it shows itself. That the world is my world, shows itself in the fact that the limits of the language (the language which I understand) mean the limits of my world.

The world and life are one.

I am my world. (The microcosm.)

The world and life are one.

I am my world. (The microcosm.)

The thinking, presenting subject; there is no such thing. If I wrote a book “The world as I found it,” I should also have therein to report on my body and say which members obey my will and which do not, etc.

It is possible, also with the old conception of logic, to give at the outset a description of all “true” logical propositions.

Hence there can never be surprises in logic.

Whether a proposition belongs to logic can be calculated by calculating the logical properties of the symbol. And this we do when we prove a logical proposition.

This process, however, has no logical foundation but only a psychological one. It is clear that there are no grounds for believing that the simplest course of events will really happen.

That the sun will rise tomorrow, is an hypothesis; and that means that we do not know whether it will rise.

A necessity for one thing to happen because another has happened does not exist. There is only logical necessity.

And they are both right and wrong. But the ancients were clearer, in so far as they recognized one clear terminus, whereas the modern system makes it appear as though everything were explained.

The world is independent of my will.

Even if everything we wished were to happen, this would only be, so to speak, a favour of fate, for there is no logical connection between will and world, which would guarantee this, and the assumed physical connection itself we could not again will.

All propositions are of equal value.

The sense of the world must lie outside the world.

In the world everything is as it is and happens as it does happen. In it there is no value—and if there were, it would be of no value.