3.02
The thoughts contains the possibility of the state of affairs which it thinks.
  What is thinkable is also possible.
3.03
We cannot think anything illogical, for otherwise we should have to think unlogically.
3.032
To present in language anything which "contradicts logic" is as impossible as in geometry to present by its co-ordinates a figure which contradicts the laws of space; or to give the co-ordinates of a point which does not exist.
3.0321
We could present spatially an atomic fact which contradicted the laws of physics, but not one which contradicted the laws of geometry.
4.002
Man possesses the capacity of constructing languages, in which every sense can be expressed, without having an idea how and what each word means-just as one speaks without knowing how the single sounds are produced.
  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.
4.06
Propositions can be true or false only by being pictures of the reality.
4.116
Everything that can be thought at all can be thought clearly. Everything that can be put into words can be put clearly.
4.1212
What can be shown cannot be said.
5.135
In no way can an inference be made from the existence of one state of affairs to the existence of another entirely different from it.
5.136
There is no causal nexus which justifies such an inference.
5.1361
The events of the future cannot be inferred from those of the present.
  Superstition is the belief in the causal nexus.
5.14
If a proposition follows from another, then the latter says more than the former, the former less than the latter.
5.44
That from a fact p an infinite number of others should follow, namely, ~~p, ~~~~p, etc., is indeed hardly to be believed, and it is no less wonderful that the infinite number of propositions of logic (of mathematics) should follow from half a dozen "primitive propositions".
  But the propositions of logic say the same thing. That is, nothing.
5.47321
Occam's razor is, of course, not an arbitrary rule nor one justified by its practical success. It simply says that unnecessary elements in a symbolism mean nothing.
  ...
d it is no less wonderful that the infinite number of propositions of logic (of mathematics) should follow from half a dozen "primitive propositions".
  But the propositions of logic say the same thing. That is, nothing.
5.47321
Occam's razor is, of course, not an arbitrary rule nor one justified by its practical success. It simply says that unnecessary elements in a symbolism mean nothing.
  ...
5.5303
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.
5.6
The limits of my language mean the limits of my world.
5.61
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.
  For that would apparently presuppose that we exclude certain possibilities, and this cannot be the case since otherwise logic must get outside the limits of the world: that is, if it could consider these limits from the other side also.
  What we cannot think, that we cannot think: we cannot therefore say what we cannot think.
5.62
This remark provides a key to the question, to what extent solip- sism is a truth.
  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 only I understand) mean the limits of my world.
5.621
The world and life are one.
5.63
I am my world. (The microcosm.)
5.631
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. This then would be a method of isolating the subject or rather of showing that in an important sense there is no subject: that is to say, of it alone in this book mention could not be made.
5.632
The subject does not belong to the world but it is a limit of the world.
5.633
Where in the world is a metaphysical subject to be noted?
  You say that this case is altogether like that of the eye and the field of sight. But you do not really see the eye.
  And from nothing in the field of sight can it be concluded that it is seen from an eye.
5.634
This is connected with the fact that no part of our experience is also a priori.
  Everything we see could also be otherwise.
  Everything we can describe at all could also be otherwise. There is no order of things a priori.
5.64
Here we see that solipsism strictly carried out coincides with pure realism. The I in solipsism shrinks to an extensionless point and there remains the reality co-ordinated with it.
5.641
There is therefore really a sense in which in philosophy we can talk of a non-psychological I.
  The I occurs in philosophy through the fact that the "world is my world".
  The philosophical I is not the man, not the human body or the human soul of which psychology treats, but the metaphysical subject, the limit-not a part of the world.
6.1
The propositions of logic are tautologies.
6.11
The propositions of logic therefore say nothing. (They are the analytical propositions.)
6.112
Theories which make a proposition of logic appear substantial are always false. One could e.g. believe that the words "true" and "false" signify two properties among other properties, and then it would appear as a remarkable fact that every proposition possesses one of these properties. This now by no means appears self-evident, no more so than the proposition "All roses are either yellow or red" would seem even if it were true. Indeed our proposition now gets quite the character of a proposition of natural science and this is a certain symptom of its being falsely understood.
6.121
The propositions of logic demonstrate the logical properties of propositions, by combining them into propositions which say nothing.
	This method could be called a zero-method. In a logical proposition propositions are brought into equilibrium with one another, and the state of equilibrium then shows how these propositions must be logically constructed.
6.126
Whether a proposition belongs to logic can be determined by determining the logical properties of the symbol.
  And this we do when we prove a logical proposition. For without troubling ourselves about a sense and a meaning, we form the logical propositions out of others by mere symbolic rules.
  We prove a logical proposition by creating it out of other logical propositions by applying in succession certain operations, which again generate tautologies out of the first. (And from a tautology only tautologies follow.)
  Naturally this way of showing that its propositions are tautologies is quite unessential to logic. Because the propositions, from which the proof starts, must show without proof that they are tautologies.
6.1261
In logic process and result are equivalent. (Therefore no surprises.)
6.1262
Proof in logic is only a mechanical expedient to facilitate the recognition of tautology, where it is complicated.
6.21
Mathematical propositions express no thoughts.
6.211
In life it is never a mathematical proposition which we need, but we use mathematical propositions only in order to infer from propositions which do not belong to mathematics to others which equally do not belong to mathematics.
6.32
The law of causality is not a law but the form of a law.
6.321
"Law of Causality" is a class name. And as in mechanics there are, for instance, minimum-laws, such as that of least action, so in physics there are causal laws, laws of the causality form.
6.3211
Men had indeed an idea that there must be a "law of least action", before they knew exactly how it ran. (Here, as always, the a priori certain proves to be something purely logical.)
6.33
We do not believe a priori in a law of conservation, but we know a priori the possibility of a logical form.
6.34
All propositions, such as the law of causation, the law of continuity in nature, the law of least expenditure in nature, etc. etc., all these are a priori intuitions of possible forms of the propositions of science.
6.363
The process of induction is the process of assuming the simplest law that can be made to harmonize with our experience.
6.3631
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.
6.36311
That the sun will rise to-morrow, is an hypothesis; and that means that we do not know whether it will rise.
6.37
A necessity for one thing to happen because another has happened does not exist. There is only logical necessity.
6.371
At the basis of the whole modern view of the world lies the illusion that the so-called laws of nature are the explanations of natural phenomena.
6.372
So people stop short at natural laws as at something unassailable, as did the ancients at God and Fate.
  And they both are right and wrong. But the ancients were clearer, in so far as they recognized one clear conclusion, whereas in the modern system it should appear as though everything were explained.
6.373
The world is independent of my will.
6.374
Even if everything we wished were to happen, this would only be, so to speak, a favour of fate, for there is no logical connexion between will and world, which would guarantee this, and the assumed physical connexion itself we could not again will.
6.4
All propositions are of equal value.
6.41
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.
  If there is a value which is of value, it must lie outside all happening and being-so. For all happening and being-so is accidental.
  What makes it non-accidental cannot lie in the world, for otherwise this would again be accidental.
  It must lie outside the world.
6.42
Hence also there can be no ethical propositions.
  Propositions cannot express anything higher.
6.421
It is clear that ethics cannot be expressed.
  Ethics are transcendental.
  (Ethics and aesthetics are one.)
6.422
The first thought in setting up an ethical law of the form "thou shalt ..." is: And what if I do not do it. But it is clear that ethics has nothing to do with punishment and reward in the ordinary sense. This question as to the consequences of an action must therefore be irrelevant. At least these consequences will not be events. For there must be something right in that formulation of the question. There must be some sort of ethical reward and ethical punishment, but this must lie in the action itself.
  (And this is clear also that the reward must be something acceptable, and the punishment something unacceptable.)
6.4311
Death is not an event of life. Death is not lived through.
  If by eternity is understood not endless temporal duration but timelessness, then he lives eternally who lives in the present.
  Our life is endless in the way that our visual field is without limit.
6.4312
The temporal immortality of the soul of man, that is to say, its eternal survival also after death, is not only in no way guaranteed, but this assumption in the first place will not do for us what we always tried to make it do. Is a riddle solved by the fact that I survive for ever? Is this eternal life not as enigmatic as our present one? The solution of the riddle of life in space and time lies outside space and time.
  (It is not problems of natural science which have to be solved.)
6.44
Not how the world is, is the mystical, but that it is.
6.5
For an answer which cannot be expressed the question too can-not be expressed.
  The riddle does not exist.
  If a question can be put at all, then it can also be answered.
6.522
There is indeed the inexpressible. This shows itself; it is the mystical.
6.53
The right method of philosophy would be this. To say nothing except what can be said, i.e. the propositions of natural science, i.e. something that has nothing to do with philosophy: and then always, when someone else wished to say something metaphysical, to demonstrate to him that he had given no meaning to certain signs in his propositions. This method would be unsatisfying to the other-he would not have the feeling that we were teaching him philosophy-but it would be the only strictly correct method.
6.54
My propositions are elucidatory in this way: he who understands me finally recognizes them as senseless, when he has climbed out through them, on them, over them. (He must so to speak throw away the ladder, after he has climbed up on it.)
  He must surmount these propositions; then he sees the world rightly.
7
Whereof one cannot speak, thereof one must be silent.