The existence of an internal property of a possible state of affairs is not expressed by a proposition, but it expresses itself in the proposition which presents that state of affairs, by an intern al property of this proposition.

It would be as senseless to ascribe a formal property to a proposition as to deny it the formal property.

4.1241    One cannot distinguish forms from one another by saying that one has this property, the other that: for this assumes that there is a sense in asserting either property of either form.