(If I fix my eyes first on the corners a and only glance at b, a appears in front and b behind, and vice versa.)
We must now answer a priori the question as to all possible forms of the elementary propositions. The elementary proposition consists of names. Since we cannot give the number of names with different meanings, we cannot give the composition of the elementary proposition.
Our fundamental principle is that every question which can be decided at all by logic can be decided offhand. (And if we get into a situation where we need to answer such a problem by looking at the world, this shows that we are on a fundamentally wrong track.)
The “experience” which we need to understand logic is not that such and such is the case, but that something is; but that is no experience.
Logic precedes every experience—that something is so.
It is before the How, not before the What.
And if this were not the case, how could we apply logic? We could say: if there were a logic, even if there were no world, how then could there be a logic, since there is a world?
Russell said that there were simple relations between different numbers of things (individuals). But between what numbers? And how should this be decided—by experience?
(There is no preeminent number.)
The enumeration of any special forms would be entirely arbitrary.
How could we decide a priori whether, for example, I can get into a situation in which I need to symbolize with a sign of a 27-termed relation?
May we then ask this at all? Can we set out a sign form and not know whether anything can correspond to it?
Has the question sense: what must be in order that anything can be the case?
It is clear that we have a concept of the elementary proposition apart from its special logical form.
Where, however, we can build symbols according to a system, there this system is the logically important thing and not the single symbols.
And how would it be possible that I should have to deal with forms in logic which I can invent: but I must have to deal with that which makes it possible for me to invent them.
There cannot be a hierarchy of the forms of the elementary propositions. Only that which we ourselves construct can we foresee.
Empirical reality is limited by the totality of objects. The boundary appears again in the totality of elementary propositions.
The hierarchies are and must be independent of reality.
If we know on purely logical grounds, that there must be elementary propositions, then this must be known by everyone who understands propositions in their unanalysed form.
All propositions of our colloquial language are actually, just as they are, logically completely in order. That simple thing which we ought to give here is not a model of the truth but the complete truth itself.
(Our problems are not abstract but perhaps the most concrete that there are.)
The application of logic decides what elementary propositions there are.
What lies in its application logic cannot anticipate.
It is clear that logic may not conflict with its application.