These maxims and the art of interpreting them may be said to constitute the premisses of science but I prefer to call them our scientific beliefs. These premisses or beliefs are embodied in a tradition, the tradition of science.

An outstanding teacher; two of his pupils won Nobel Prizes. He emigrated to Germany working at the Kaiser Wilhelm Institute and then to England working at the University of Manchester. He pioneered the theory of fiber diffraction analysis in 1921 and the dislocation theory of plastic deformation of ductile metals and other materials in 1934.