[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.

Roger Jones

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