In preparing the eighth edition of my Handboek van de Economie (an earlier edition has been translated into English, Economics a critical approach), the contents have been divided into two parts. Whereas the flrst part deals with economic theory as such, the present publication contains the subject matter of the second part, namely, the critical comments on various economic theories. Here I have taken into consideration the opinions expressed in reviews of the aforementioned book and by several colleagues. While some indicated that 'The "appraisal" sections cater for the sceptical intelligent student' (C.D. Harbury, Economica, August 1972), other teachers judge that 'students who demand "relevance" from their studies are not likely to last long with a book which follows each point by a note stating that it is really pretty useless' (J. R. S. Revell, The Economic Journal, September 1972). This book has no intentions of instructing fellow economists. It is intended as a complement to an introductory course on economics, which for the most part does not deal systematically with (or is even totally lacking in) critical comments. This also explains why a survey of the main trends in economic doctrine are found in the Appendix. Many economists consider any criticism of economic theory to be a form of v PREFACE vi Zese-majeste. On the other hand, a critical approach should not be the monopoly of Marxist or gauchist authors.