point on the sheet, whether it is black or white. To the fact that a point
is black there corresponds a positive fact, and to the fact that a point is
white (not black), a negative fact. If I designate a point on the sheet (a
truth-value according to Frege), then this corresponds to the supposition
that is put forward for judgement, etc. etc. But in order to be able to say
that a point is black or white, I must first know when a point is called
black, and when white: in order to be able to say,'"p" is true (or false)',
I must have determined in what circumstances I call 'p' true, and in so
doing I determine the sense of the proposition. Now the point where the
simile breaks down is this: we can indicate a point on the paper even if we
do not know what black and white are, but if a proposition has no sense,
nothing corresponds to it, since it does not designatea thing (a truth-
value) which might have properties called 'false' or 'true'. The verb of a
proposition is not 'is true' or 'is false', as Frege thought: rather, that
which 'is true' must already contain the verb.


4.064 Every proposition must already have a sense: it cannot be given a
sense by affirmation. Indeed its sense is just what is affirmed. And the
same applies to negation, etc.


4.0641 One could say that negation must be related to the logical place
determined by the negated proposition. The negating proposition determines
a logical place different from that of the negated proposition. The
negating proposition determines a logical place with the help of the
logical place of the negated proposition. For it describes it as lying
outside the latter's logical place. The negated proposition can be negated
again, and this in itself shows that what is negated is already a
proposition, and not merely something that is prelimary to a proposition.