Theor Med Bioeth (2014) 35:315–319 DOI 10.1007/s11017-014-9298-0
Raffaella Campaner: Philosophy of medicine: causality, evidence and explanation Archetipo Libri, Bologna, 2012, xiii + 171 pp, €16.00 (softcover), ISBN: 978-8-866-33093-6 Jeremy R. Simon
Published online: 5 June 2014 Ó Springer Science+Business Media Dordrecht 2014
The present volume is one of a type (collected papers by a single author on a topic) we should soon expect to be seeing more of in philosophy of medicine. Philosophy of medicine has now been around long enough that entire careers, or at least substantial portions of careers, can and have been devoted to it. This is an important milestone in the field. This is true, even though, as the author indicates in the introduction, this is not solely a book of philosophy of medicine. Investigations in philosophy of medicine, and the essays included in this volume in particular, can not only contribute to ‘‘the development of philosophy of medicine as a discipline’’ (p. xiii) but can also ‘‘test and help revise some of [philosophy of science’s] views’’ (p. x). Thus, this book is intended as a contribution both to philosophy of medicine as a specific discipline and to philosophy of science generally. Both of these aspects of the book could attract the attention of the current audience. The book focuses on issues of causality and explanation, with particular emphasis on the concept of mechanism. The papers are all recent (the earliest was published in 2006), with two forthcoming at the time of publication and one (the last in the volume) apparently still in press. By and large, they focus on somatic medicine, or medicine generally, but the final two papers deal specifically with psychiatric disease. Chapter 1 begins by highlighting the multilevel nature of the causes of disease. Not only are there levels within the organism, such as molecules, cells, and organs, but more broadly, there also are epidemiological factors, such as birthplace, occupation, and where one lives. Psychiatry offers further levels to consider, such as past traumas and family relationships. Because of this multilevel feature of medicine, Campaner proposes that mechanisms, the structures of which allow J. R. Simon (&) Department of Medicine and Center for Bioethics, Columbia University, 622 W. 168th St, PH 2-260, New York, NY 10025, USA e-mail:
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different levels to interact, are a particularly apt way of understanding diseases. They can be used to understand disease development and diffusion, as well as to help generalize beyond specific case studies. In particular, mechanisms can help us to understand causation, and even more specifically, how causal factors interact to bring about diseases, though Campaner acknowledges that developing a theoretical understanding of how different levels can interact is still a challenge; how do higher level social factors, for example, interact with the biochemical pathways of a disease? Campaner also discusses interventionist approaches to disease causation, which she feels may be useful given that the mechanisms we develop for diseases are often merely sketches, with many gaps. Interventionist accounts, in which causation is understood not in terms of the workings of a mechanism but rather in terms of how things would have been different had a given intervention occurred (or not occurred), are often presented as alternatives to mechanistic approaches; Campaner believes that the two can be complementary and need not rule the other out. Campaner concludes that consideration of diseases can lead, both for philosophy of medicine as well as philosophy of science generally, to adopting a flexible account of mechanisms that draws on various accounts of mechanism as well as a pluralistic approach to explanation that can accommodate multiple levels of organization and abstraction. Chapter 2 focuses more specifically on mechanisms. Campaner begins by considering mechanistic accounts of causation and understanding of mechanisms, using, as a starting point, Wesley Salmon’s ‘‘mark transmission’’ theory of causation, where a truly causal process will transmit a ‘‘mark,’’ or modification, without further interaction. She then moves on to a discussion of accounts such as those of Peter Machamber, Lindley Darden and Carl Craver, Stuart Glennan, and William Bechtel and Adele Abrahamsen, each of whom uses a somewhat different notion of mechanisms in dealing with explanation and causation. In particular, she discusses the relevance of these accounts to medicine. But her focus is on Federica Russo and Jon Williamson and their distinction between mechanistic and probabilistic evidence in medicine. Campaner believes that the distinction is meaningful, but that the two forms of evidence cannot be separated as Russo and Williamson want. Rather, the two types of evidence act together, with probabilistic evidence helping to generate and fill in new mechanistic hypotheses, which can then underlie further mechanistic reasoning. Thus, again, for Campaner, causation and explanation in medicine should be understood pluralistically. Chapter 2 draws its examples primarily from clinical medicine, using H. pylori and hepatocellular carcinoma in particular. Chapter 3 considers causation and explanation in epidemiology. The chapter starts with a review of the historical progress of causal paradigms in epidemiology, from the ‘‘miasma paradigm’’ to ‘‘eco-epidemiology,’’ the latter of which understands epidemiological causation in terms of the interaction of factors at different levels. Campaner then notes that epidemiology has begun to talk of mechanisms, and moves into a review of accounts of mechanisms, similar to that of the preceding chapter, but adding in particular a consideration of James Woodward’s work. Campaner says that given epidemiology’s focus on different levels of causally and explanatorily relevant factors, mechanisms are again an apt approach. As before, however, mechanistic
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approaches need to be supplemented and supported by interventionist evidence. Finally, she notes that, as a full mechanistic explanation requires taking into account all relevant factors, which in general cannot happen, the quest for mechanisms should be taken more as an aspirational goal to get epidemiologists thinking in the right way than as something practically to be expected. Chapter 4 has only a tangential relationship to philosophy of medicine as such. The chapter starts with a review of Salmon’s account of causation, followed by a discussion of Phil Dowe’s Conserved Quantity (C-Q) approach, in which a causal process is one that involves a conserved quantity such as mass, energy, or momentum. The chapter then discusses mechanistic approaches, particularly that of Machamber, Darden, and Craver, focusing particularly on their accounts of causation. All of these accounts, which are taken to be philosophical analyses of causation, removed from everyday usage of the term, are contrasted with manipulative accounts of causation, descending from R.G. Collingwood and H.L.A. Hart, which are more pragmatic, understanding causation in terms of what happens when we manipulate variables in the system. In particular, Campaner focuses on the agency theory of Huw Price and Peter Menzies. She then considers whether these two types of accounts are mutually exclusive or whether they can be integrated in any way. She reviews various pluralistic discussions of causation, including those of Maria Carla Galavotti, Donald Gillies, James Woodward, and Nancy Cartwright, among others, and concludes that pluralism in causation is attractive but that more work needs to be done to arrive at ‘‘a plausible and coherent view [that] will be settled on and shared’’ (p. 60). Of note is that other than mentioning briefly that Gillies was specifically addressing medicine in developing his account, the chapter does not deal with philosophy of medicine as such. In Chapter 5, co-authored with Maria Carla Galavotti, Campaner continues her discussion of pluralism in causation and applies it more directly to medicine. The chapter begins much like the previous one, starting with Salmon, turning to the mechanistic approaches of Glennan and Machamber, Darden, and Craver, and then discussing the manipulative accounts of Price and Menzies, and Woodward. After this lengthy review, the paper briefly presents an argument for pluralism in causation in econometrics, originally made by Galavotti (with Guido Gambetta). There the problem is seen to be the difficulty in moving between individual and group behavior in economics. In classical philosophical terms, the problem is moving between discussions of token causation, which explains individual events, and type causation, which explains the occurrence of entire classes of similar events. The main thrust of the paper then follows, with a detailed case discussion of deep brain stimulation for Parkinson’s disease used to make a similar argument in the case of medicine. Chapter 6 explores another approach to causation with the use of two extended medical examples. In this chapter, Campaner discusses Lewis’s counterfactual account of causation, and in particular, the problems raised by cases of pre-emption, where the effect would have happened even in the absence of the cause because, in that case, a secondary cause would have brought about the effect in question. She then presents the cases of HIV treatment and cancer chemotherapy. What these two cases have in common, in particular, is that both often involve multiple drugs, which seek to destroy the cells in question through different mechanisms, in effect, producing opportunities for
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pre-emption of a downstream mechanism by one that acts earlier in a given metabolic pathway or lifecycle. This structure of clinical thinking in approaching therapeutics, attempting to strike at multiple points, is then taken to exemplify ‘‘preempting causation’’ (p. 95); this shows how philosophy of science can help us make sense of clinical reasoning. In return, says the author, we also see that medicine can provide test cases for working out problematic issues in philosophy of science. Chapter 7 goes in a somewhat different direction, while still staying close to the theme of the book. Noting that reductionism and reductive explanations have become well entrenched in science generally, including molecular biology, Campaner asks whether they can serve health sciences equally well. She first examines whether reductionism is compatible with the mechanistic approach to medicine covered earlier in the book, and cites two opposite conclusions to this question. She then cites several objections to reductionism in medicine, such as the concern that it leaves no room for the patient as a person, or for other psychosocial aspects of medicine. She also cites Marc H. V. Van Regenmortel, who argues that reductionism interferes with the ability to develop new drug therapies because it makes it difficult to focus on the overall system (a sick human) in which these therapies must function, as well as other similar critiques. Noting, however, that reductionism has its uses despite these critiques, Campaner concludes by arguing for a pluralistic approach to medical explanation, encompassing both reductionist and non-reductionist approaches. Chapters 8 and 9 shift focus to psychiatry specifically. Chapter 8 opens with some of the particular difficulties in dealing with psychiatric diseases philosophically, including the presence of both reductionist and non-reductionist approaches to mental illnesses as well the intrinsic involvement of first-person experiences in these diseases. Campaner then moves on to discuss mechanistic and nonmechanistic approaches to causation in mental disease. Much of the ground covered has been seen earlier in the book, such as work by Craver and Woodward, but she also brings in John Campbell and Kenneth Schaffner, who deal specifically with mental illness. As elsewhere, this multiplicity of approaches leads Campaner to conclude with a call for explanatory pluralism in dealing with mental illness. The final chapter discusses models of psychiatric illnesses. It begins again with a discussion of the special philosophical problems of psychiatry, similar to that of the preceding chapter. This is followed by a discussion of the various models proposed for mental illness, such as the biological, behavioral, cognitive, and social realist models, and the difficulties that can arise if different members of a team adopt different models for the same diseases. Drawing on work by Kenneth Kendler in particular, Campaner proposes that explanatory pluralism can help mitigate such problems by providing a framework within which the various explanatory paradigms can interact with and accommodate each other. As noted at the outset, it is exciting to read a collection of papers on philosophy of medicine. The book does, however, have a narrow focus, essentially being an extended argument for pluralism in causation and explanation both in philosophy of medicine and philosophy of science. Unfortunately, rather than complementing each other to produce a stronger argument than they can individually, the papers overlap each other in ways that seem redundant. The author would have done better to have
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reorganized the material to eliminate redundancy. This would have had the further benefit of allowing her to go more in depth. Although we hear often about Wesley Salmon, James Woodward, and Machamber, Darden, and Craver, none of the presentations are detailed enough to allow one who is not already familiar with their positions to understand them. This is reasonable in an article, but with a full book to work with, it is less than satisfying. Similarly, Campaner could have presented a comprehensive account of the pluralism she favors, rather than simply addressing it in the conclusion of each chapter, and a more robust and unified argument for it, rather than multiple small arguments based on the contents of each chapter. That said, there is much to be gleaned from this book. Campaner writes thoughtfully on the relationships between different accounts of causation, mechanisms, and explanation, and the possibility of reconciling, or at least combining them, and does this in many fields across medicine. A reader who is unfamiliar with these accounts will be well served by this introduction to them, though he or she will likely need to turn to the original sources for more details. Similarly, Campaner’s pluralism is thought provoking and well worth thinking about. I hope that she will further develop the papers presented in this volume as a monograph.
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