gic out
of its primitive signs must be made clear.

5.451 If logic has primitive ideas, they must be independent of one
another. If a primitive idea has been introduced, it must have been
introduced in all the combinations in which it ever occurs. It
cannot, therefore, be introduced first for one combination and
later reintroduced for another. For example, once negation has been
introduced, we must understand it both in propositions of the form
'Pp' and in propositions like 'P(p C q)', '(dx). Pfx', etc. We must not
introduce it first for the one class of cases and then for the other,
since it would then be left in doubt whether its meaning were the same
in both cases, and no reason would have been given for combining the
signs in the same way in both cases. (In short, Frege's remarks about
introducing signs by means of definitions (in The Fundamental Laws
of Arithmetic ) also apply, mutatis mutandis, to the introduction of
primitive signs.)

5.452 The introduction of any new device into the symbolism of logic
is necessarily a momentous event. In logic a new device should not
be introduced in brackets or in a footnote with what one might call
a completely innocent air. (Thus in Russell and Whitehead's Principia
Mathematica there occur definitions and primitive propositions expressed
in words. Why this sudden appearance of words? It would require a
justification, but none is given, or could be given, since the procedure
is in fact illicit.) But if the introduction of a new device has proved
necessary at a certain point, we must immediately ask ourselves, 'At
what points is the employment of this device now unavoidable?' and its
place in logic must be made clear.

5.453 All numbers in logic stand in need of justification. Or rather,
it must become evident that there are no numbers in logic. There are no
pre-eminent numbers.

5.454 In logic there is no co-ordinate status, and there can be no
classification. In logic there can be no distinction between the general
and the specific.

5.4541 The solutions of the problems of logic must be simple, since they
set the standard of simplicity. Men have always had a presentiment
that there must be a realm in which the answers to questions are
symmetrically combined--a priori--to form a self-contained system. A
realm subject to the law: Simplex sigillum veri.

5.46 If we introduced logical signs properly, then we should also have
introduced at the same time the sen