When I use "materialism", it is not of course meant pejoratively, but only in the philosophical sense that physical matter is the only reality. However, you say "modern physics makes the distinction between material and immaterial more difficult to maintain in this nineteenth century sense". - Physical matter is not the only reality. The quantum level underlies everything as I think George was inferring.This article on the attempt at quantum computing demonstrates: - http://www.nature.com/news/2009/090628/full/news.2009.603.html