Tractatus Logico-Philosophicus | Page 4

create anything except what
would be contrary to the laws of logic. The truth is that we could not
say what an 'illogical' world would look like.
3.032 It is as impossible to represent in language anything that
'contradicts logic' as it is in geometry to represent by its coordinates a
figure that contradicts the laws of space, or to give the coordinates of a
point that does not exist.
3.0321 Though a state of affairs that would contravene the laws of
physics can be represented by us spatially, one that would contravene

the laws of geometry cannot.
3.04 It a thought were correct a priori, it would be a thought whose
possibility ensured its truth.
3.05 A priori knowledge that a thought was true would be possible only
it its truth were recognizable from the thought itself (without anything a
to compare it with).
3.1 In a proposition a thought finds an expression that can be perceived
by the senses.
3.11 We use the perceptible sign of a proposition (spoken or written,
etc.) as a projection of a possible situation. The method of projection is
to think of the sense of the proposition.
3.12 I call the sign with which we express a thought a propositional
sign. And a proposition is a propositional sign in its projective relation
to the world.
3.13 A proposition, therefore, does not actually contain its sense, but
does contain the possibility of expressing it. ('The content of a
proposition' means the content of a proposition that has sense.) A
proposition contains the form, but not the content, of its sense.
3.14 What constitutes a propositional sign is that in its elements (the
words) stand in a determinate relation to one another. A propositional
sign is a fact.
3.141 A proposition is not a blend of words.(Just as a theme in music is
not a blend of notes.) A proposition is articulate.
3.142 Only facts can express a sense, a set of names cannot.
3.143 Although a propositional sign is a fact, this is obscured by the
usual form of expression in writing or print. For in a printed
proposition, for example, no essential difference is apparent between a
propositional sign and a word. (That is what made it possible for Frege

to call a proposition a composite name.)
3.1431 The essence of a propositional sign is very clearly seen if we
imagine one composed of spatial objects (such as tables, chairs, and
books) instead of written signs.
3.1432 Instead of, 'The complex sign "aRb" says that a stands to b in
the relation R' we ought to put, 'That "a" stands to "b" in a certain
relation says that aRb.'
3.144 Situations can be described but not given names.
3.2 In a proposition a thought can be expressed in such a way that
elements of the propositional sign correspond to the objects of the
thought.
3.201 I call such elements 'simple signs', and such a proposition
'complete analysed'.
3.202 The simple signs employed in propositions are called names.
3.203 A name means an object. The object is its meaning. ('A' is the
same sign as 'A'.)
3.21 The configuration of objects in a situation corresponds to the
configuration of simple signs in the propositional sign.
3.221 Objects can only be named. Signs are their representatives. I can
only speak about them: I cannot put them into words. Propositions can
only say how things are, not what they are.
3.23 The requirement that simple signs be possible is the requirement
that sense be determinate.
3.24 A proposition about a complex stands in an internal relation to a
proposition about a constituent of the complex. A complex can be
given only by its description, which will be right or wrong. A
proposition that mentions a complex will not be nonsensical, if the
complex does not exits, but simply false. When a propositional element

signifies a complex, this can be seen from an indeterminateness in the
propositions in which it occurs. In such cases we know that the
proposition leaves something undetermined. (In fact the notation for
generality contains a prototype.) The contraction of a symbol for a
complex into a simple symbol can be expressed in a definition.
3.25 A proposition cannot be dissected any further by means of a
definition: it is a primitive sign.
3.261 Every sign that has a definition signifies via the signs that serve
to define it; and the definitions point the way. Two signs cannot signify
in the same manner if one is primitive and the other is defined by
means of primitive signs. Names cannot be anatomized by means of
definitions. (Nor can any sign that has a meaning independently and on
its own.)
3.262 What signs fail to express, their application shows. What signs
slur over, their application says clearly.
3.263