1. skeptical philosophy of Pyrrho: the doctrine of the ancient Greek philosopher Pyrrho, who believed that it was impossible to be certain about anything and therefore suspended judgment on everything
2. complete skepticism: skepticism to an extreme or excessive degree
[Late 17th century. < Greek Purrhōn "Pyrrho" (360?-272?bce), Greek philosopher]
Pyr·rhon·ist noun, adjective
msn.com. Encarta® World English Dictionary http://encarta.msn.com/dictionary_/Pyrrhonism.html (accessed: September 26, 2008).
Bob's pyrrhonism ran very deep. He questioned his own motives and actions so harshly that he often refused to talk to himself for weeks at a time.