p" As, for instance, when one would
speak of the archtype Proposition, Thing, etc. So Russell in
the Princples of Mathematics has rendered the nonsense
"p is a proposition" in symbols by
"p p" and has put it as hypothesis before
certain propositions to show that their places for arguments
could only be occurpied by propositions.
(It is nonsense to place the hypothesis
p p before a proposition in order to ensure that
its arguments have the right form, because the hypotheses for a
non-proposition as arugment becomes not false but meaningless,
and because the proposition itself becomes senseless for
arguments of the wrong kind, and therefore it survives the
wrong arguments no better and no worse than the senseless
hypthesis attached for this purpose.)