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Review of "Philosophy and Psychotherapy"

By Edward Erwin
Sage Publications, 1996
Review by Lisa Bortolotti on Apr 17th 2002
Philosophy and Psychotherapy

In this interesting book, Erwin addresses some issues concerning the justification of psychotherapy as a remedy for psychological disorders. In particular, he discusses some of the criteria for the assessment of psychotherapy, such as the obtainability of its aims and its success in improving the condition of clients. The merit of the analysis Erwin offers is to provide a well-informed and accessible account of the current state of psychotherapy, its history and its philosophical grounds.

Erwin's book is supposed to fill a gap in the literature on psychotherapy. Few philosophers have shown an interest in issues related to the foundations and practice of psychotherapy and practitioners have been reflecting too little on the general purposes and overall success of their discipline.

In the first part of the book, Erwin addresses what he calls "foundational questions", what the aim of psychotherapy is, how psychotherapy can achieve its goals, what epistemic standards should be relevant for the evaluation of psychotherapeutic evidence.

In the second part, he reviews three paradigms in psychotherapy, the behavioristic, the cognitive and the psychoanalytic.

In the epilogue, Erwin concludes that psychotherapy is successful only in so far as it has a placebo effect on the client. The reason for this claim is that, according to the author, we lack satisfactory evidence for regarding any treatment factor of psychotherapy as remedial for the disorders that might affect the client.

Erwin's argumentative skills and knowledge of the literature are remarkable and most of his original claims are persuasive. Although I am largely sympathetic to his critical approach to psychotherapy, I found his final conclusion not entirely supported by his previous discussion. My main worry is that Erwin sets unrealistically high standards for the adequacy of evidence for the success of psychotherapy. Let me offer an example here.

Erwin addresses the issue of how we can establish the truth of psychotherapeutic hypotheses that posit unobservable states such as repressed wishes. One option is to rely on the inference to the best explanation. The idea is that we posit the existence of unobservable entities to explain some observable phenomena. If we manage to predict the observable phenomena on the basis of the behavior of the entities whose existence we have posited, then we have reasons to believe that our explanation is a good one. Whether the hypothesis is the best available will depend on epistemological criteria (e.g. internal consistency) and pragmatic considerations (e.g. simplicity). Erwin is not persuaded by the reliability of this method. He writes: "However one decides what is the best available explanation of certain data, does the fact that it is the best one anyone can think of suffice for having grounds for thinking the hypothesis is true?" (page 77). Erwin concludes that the inference to the best explanation is too low a standard for judging therapeutic hypotheses.

I think Erwin's conclusion is too quick. The inference to the best explanation is a legitimate scientific tool for the generation and acceptance of hypotheses about all sorts of phenomena. If we had not relied on inference to the best explanation to some extent, we would not have posited the existence of electrons, or other unobservable entities that play an important role in the explanation of physical phenomena. The point to keep in mind is that the generation of a hypothesis is only the first step towards its acceptance. Once the hypothesis is on the table, it needs to be verified via experimental evidence and it needs to outcompete other available hypotheses in terms of predictive success and explanatory power. Moreover, the hypothesis has to resist revision in order to become part of our dominant theory about the phenomena under investigation. Even though the initial formulation of the hypothesis might be little more than an informed guess, the competition with alternative explanations and the necessity of empirical confirmation contribute to setting high standards for the acceptance of the hypothesis.

Erwin invites us to consider whether psychotherapy can be a science. This is an important question that needs an answer. But Erwin's answer is biased if he claims that the standards for the acceptance of a psychotherapeutic hypothesis need to be higher than the standards for the acceptance of a scientific hypothesis. Erwin is right to put pressure on the criteria according to which we evaluate hypotheses in psychotherapy and to ask for a more rigorous examination of the available evidence. Yet, some of Erwin's observations throughout the book suggest that not many hypotheses in psychotherapy or any other discipline would count as well grounded in the light of his demanding criteria.


© 2002 Lisa Bortolotti


Lisa Bortolotti studied philosophy in Bologna (Italy), London and Oxford (UK) before starting her PhD at the Australian National University in Canberra. Her main interests are in philosophy of mind, philosophy of psychology, rationality, mental illness and animal cognition.