Z A Melzak 1983 Chichester: John Wiley 245 pp price £33.20 ISBN 0 471 86854 X The 'simple approach to complexity' advocated in this book is hardly novel: transform a given problem to one more easily solved, solve it and invert the transformation to arrive at the required solution. This is formalised by the 'conjugacy principle' or similarity transformation WESTS'1; the difficulty is to find the appropriate transformation 5.