[FOM] Could PA be inconsistent?

[Martin Davis]

There are now two threads going on FOM contemplating this possibility. No 
one has mentioned that we possess proofs that PA is consistent. These 
proofs can be carried out in quantifier-free primitive recursive arithmetic 
with induction permitted on a primitive recursive well-ordering of the 
natural numbers of order type epsilon-0. These proofs (Gentzen, Ackermann, 
G\"odel) have gone unchallenged for decades.

Martin