s that we can actually do without logical
propositions; for in a suitable notation we can in fact recognize the
formal properties of propositions by mere inspection of the propositions
themselves.

6.1221 If, for example, two propositions 'p' and 'q' in the combination
'p z q' yield a tautology, then it is clear that q follows from p. For
example, we see from the two propositions themselves that 'q' follows
from 'p z q. p', but it is also possible to show it in this way: we
combine them to form 'p z q. p:z: q', and then show that this is a
tautology.

6.1222 This throws some light on the question why logical propositions
cannot be confirmed by experience any more than they can be refuted by
it. Not only must a proposition of logic be irrefutable by any
possible experience, but it must also be unconfirmable by any possible
experience.

6.1223 Now it becomes clear why people have often felt as if it were
for us to 'postulate' the 'truths of logic'. The reason is that we can
postulate them in so far as we can postulate an adequate notation.

6.1224 It also becomes clear now why logic was called the theory of
forms and of inference.

6.123 Clearly the laws of logic cannot in their turn be subject to
laws of logic. (There is not, as Russell thought, a special law of
contradiction for each 'type'; one law is enough, since it is not
applied to itself.)

6.1231 The mark of a logical proposition is not general validity. To be
general means no more than to be accidentally valid for all things.
An ungeneralized proposition can be tautological just as well as a
generalized one.

6.1232 The general validity of logic might be called essential, in
contrast with the accidental general validity of such propositions
as 'All men are mortal'. Propositions like Russell's 'axiom of
reducibility' are not logical propositions, and this explains our
feeling that, even if they were true, their truth could only be the
result of a fortunate accident.

6.1233 It is possible to imagine a world in which the axiom of
reducibility is not valid. It is clear, however, that logic has nothing
to do with the question whether our world really is like that or not.

6.124 The propositions of logic describe the scaffolding of the world,
or rather they represent it. They have no 'subject-matter'. They
presuppose that names have meaning and elementary propositions sense;
and that is their connexion with the world. It is clear that so