I will keep this very brief. I am an electrical engineer and computer scientist, and, after a couple of decades in the "commercial world" , am always amazed at the "unreal effectiveness" of mathematics when applied to this and the real world. Bell's book captures this essence in a timeless tome that must be required reading and regular re-reading for all aspiring. and indeed, practising, mathematicians, engineers and scientists. It is a source of both inspiration and "bringing back to earth" to those that read it. No serious practitioners library should be without it.