Mahoney's recent book, Cognition and Behaviour Modification (1974), has produced some fierce interchanges in the pages of this journal. To me, the surprising feature of the controversy is that it has frowned on Mahoney's arguments about the adequacy of radical behaviourism. I had imagined that the philosophical assumptions of radical behaviourism had long ago been shown to be untenable. However, I do not wish to join in this discussion, or to try and improve on the arguments of Mahoney and Marzillier's (1976) defence of them.

In 1958 Stunkard and McLaren-Hume concluded that “Most obese persons will not remain in treatment, of those that remain in treatment, most will not lose weight, of those that do lose weight, most will regain it.” Since then great advances have been claimed for behavioural, specifically self-control, treatments of obesity, (i.e. Stunkard, 1972). This had been witnessed in a great proliferation of research papers on group studies purporting to demonstrate the superiority of this approach and to verify its theoretical basis.