Pelicans ISBN 0 14 02.1900 5 - Practical Thinking 4 ways to be right; 5 ways to be wrong; 5 ways to understand

Penguin Books Ltd, Harmondsworth, Middlesex, England Penguin Books Inc, 625 Madison Avenue, New York New York 10022, U.S.A. Penguin Books Australia Ltd, Ringwood, Victoria, Australia Penguin Books Canada Ltd, 2801 John Street, Markham, Ontario, Canada L3R 1B4 Penguin Books (N.Z.) Ltd, 182-190 Wairau Road, Auckland 10, New Zealand

First published by Jonathan Cape 1971 Published in Pelican Books 1976 Reprinted 1976, 1977, 1978

Text copyright © European Services Ltd, 1971 Illustrations copyright © Jonathan Cape Ltd, 1971 All rights reserved

Made and printed in Great Britain by Cox & Wyman Ltd, London, Reading and Fakenham Set in Monotype Times

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