For in the printed proposition, for example, the sign of a proposition does not appear essentially different from a word.
(Thus it was possible for Frege to call the proposition a compounded name.)
3.1431
The essential nature of the propositional sign becomes very clear when we imagine it made up of spatial objects (such as tables, chairs, books) instead of written signs.
The mutual spatial position of these things then expresses the sense of the proposition.
3.1432
We must not say, “The complex sign ‘aRb’ says ‘a stands in relation R to b’ ”; but we must say, “That ‘a’ stands in a certain relation to ‘b’ says that aRb”.
3.144
States of affairs can be described but not named.
(Names resemble points; propositions resemble arrows, they have sense.)
3.2
In propositions thoughts can be so expressed that to the objects of the thoughts correspond the elements of the propositional sign.
3.201
These elements I call “simple signs” and the proposition “completely analysed.”
3.202
The simple signs employed in propositions are called names.
3.203
The name means the object. The object is its meaning. (“a” is the same sign as “a”.)
3.21
To the configuration of the simple signs in the propositional sign corresponds the configuration of the objects in the state of affairs.
3.22
In the proposition the name represents the object.
3.221
Objects I can only name. Signs represent them. I can only speak of them. I cannot assert them. A proposition can only say how a thing is, not what it is.
3.23