Re: Logic must "look after itself"

translogi wrote:
Found your quote

it is in the tractatus

5.473 Logic must look after itself. If a sign is possible , then it is
also capable of signifying. Whatever is possible in logic is also
permitted. (The reason why 'Socrates is identical' means nothing is
that there is no property called 'identical'. The proposition is
nonsensical because we have failed to make an arbitrary determination,
and not because the symbol, in itself, would be illegitimate.) In a
certain sense, we cannot make mistakes in logic.


I think Wittgenstein was also wrong here.

He like Russell was very into what we now call classical logic,
(inclusdes the law of the excluded middle )
Classical logic at that time was still very new.

Wittgenstein was also very in to truthtables and thought that every
logical statement can be SHOWN to be true by a truthtable

Guess we now know better

What do you think is logic?

I don't know about Witts truth tables, but I certainly doon't think that we now know better if that's Godels doing.

I thought logic was about reducing instances to general cases and presenting it in a way that copies the physical presence of physical objects, using brackets, single letters (often where each letter counts as an one object), etc. This helps in bulk calculation, just like arithmetic.
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