[hist-analytic] The Two Color Problem, Putnam, and the Synthetic A Priori
Roger Bishop Jones
rbj at rbjones.com
Wed Nov 4 11:00:52 EST 2009
Though I have not been following this thread closely, I did look at Bruce's
proof, and find it to be unsound for the following reason.
The purported definition D1 for the function DC is problematic as it stands.
For this to constitute a definition it would be necessary first for us to have a
definition of the phrase "x has A at t", and secondly for us to know that
whenever x has A at t and x has B at t then A = B.
The definition therefore depends for its validity on the principle for the
proof of which it was defined.
This is a proof by Petitio Principii.
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