Materials science: Parepistemes rampant

This article is based on a plenary address which Robert W. Cahn, Cambridge University, delivered at the International Union of Materials Research Soci eties International Conference on Advanced Materials (IUMRS-ICAM'99) hosted by the Chinese Materials Research Society (C-MRS) in Beijing, oil June 14, 1999. A version of this article is also being published in Materials Today , the quarterly magazine published by Elsevier for the European-MRS. A repo rt of the IUMRS-ICAM'99 meeting will he published in a future issue of MRS Bulletin.