IN the good old days when business was business, and nothing more, the books which executives in industry and commerce were most apt to read fell into two broad classifications. There were first the general books on economics, for the most part theoretical treatises in the classical tradition. Then there were volumes more practical in their purpose, on how to increase production, how to promote efficiency, how to ‘pep up’ the sales force. To-day the business man must be something more than a narrow specialist in his field, for in 1935 he is pricked on every side by problems which, were once considered the sole concern of politicians, or of sociologists, or even of philosophers. Symptomatic of this deep change are the volumes which are included in this month’s selection.