Rationality and Compulsion is a very useful resource for those philosophers of mind who might wonder what the practical dimension of their work is, and to those psychiatrists who are interested in the philosophical issues raised by the study of mental disorders. Nordenfelt has the great merit of writing clearly and developing the book around a very transparent structure. First, he combines his insights in philosophy of action and philosophy of health to create a solid theoretical apparatus, and then draws from that some conclusions about rationality that he applies to the case of compulsion. The theses put forward are well-argued and overall convincing, although the reader sometimes gets the impression that they are being rushed through a very intricate terrain and not made totally aware of the implications of what they are tempted to agree with. But this is inescapable in an ambitious work such as Nordenfelt's.

My concerns are of a different sort. The book does exactly what it says on the tin: it applies action theory to psychiatry. Methodologically, this is a fairly safe option. Take a theory which explains when certain actions are rational, and use it to answer the question of whether a certain type of behaviour occurring in a certain type of mental disorder can be legitimately characterised as an instance of intentional behaviour which satisfies the relevant norms of rationality. If you think the theory works, and has advantages over its competitors, then you will get a good illustration of it by throwing in some interesting examples from psychiatry, where an initially puzzling phenomenon is made clearer by the application of the theory of your choice.

However, this is a classic case of imposing independently motivated theoretical distinctions onto real-life problems without properly acknowledging that the analysis of those problems can feed back into the theory. The study of mental disorders does not simply illustrate how elegantly our theoretical commitments can provide answers to questions about intentionality and rationality. Rather, it helps us redefine what intentionality and rationality are. Regrettably, there is little of this feedback loop in Nordenfelt's work.