In the 1976 Philosophy of Science Association symposium on the philosophy of medicine and its relationship to the philosophy of science, Tristram Engelhardt also responded to Shaffer's assertion that "there is no subject matter unique to medicine for a philosophy of medicine to address" (1977, p. 94). To the question, "Is there a philosophy of medicine?," which also served as the title of his lecture, Engelhardt not only gave an affirmative answer but delineated weak and strong senses for a philosophy of medicine. The weak sense pertains to issues such as bioethics and mind-body dualism and is comparable to Pellegrino's philosophy in medicine. In a strong sense philosophy of medicine is concerned with notions specific to medicine, such as health and disease. What distinguishes philosophy of medicine from philosophy of biology is that the notions of health and disease are not so much species problems but individual human problems: "What counts as health and disease for humans depends upon very complex judgments concerning suffering, the goals proper to humans, and, for that matter, the form or appearance proper to humans" (Engelhardt, 1977, p. 102).
In editorial remarks to a special issue of The Journal of Medicine and Philosophy, which marked the journal's decennial issue, Engelhardt reviewed the rise of contemporary philosophy of medicine as a discipline, including the founding of the journal, the establishment of a President's Commission, and numerous books and essays on the subject. "There is now," concluded Engelhardt, "a philosophy of medicine. To demonstrate its existence, one need not be able to show that the issues examined in the philosophy of medicine are irreducible to issues in other branches of philosophy. Though this likely can be shown," he continued, "it is enough to demonstrate the success of examining together the cluster of philosophical issues that has come to constitute the philosophy of medicine. The last decade has more than established this point" (1986a, p. 7).
Pellegrino followed these comments with an essay, in which he argued on two counts for the existence of philosophy of medicine as a distinct discipline. The first is that medicine is not simply the summation of the individual disciplines that comprise it. "Medicine," claimed Pellegrino, "calls upon insights, knowledge, skills, and techniques from science, art, and the humanities, but for a distinctive and defined end [healing this patient] that is not the end of any of these other disciplines. The philosophy of medicine, therefore," he concluded, "is not synonymous with the philosophy of biology, literature, history, or sociology, though each may contribute to medicine's specific enterprise" (1986, p. 13). The second count is that philosophy of medicine is distinct from medicine itself. Philosophy of medicine, although examining issues that overlap with medicine, treats medicine, however, as its subject matter. Again, Pellegrino concluded that philosophy of medicine "seeks to understand and define the conceptual substrata of medical phenomena" (1986, p. 14).
In the early 1990s Arthur Caplan argued that although there is no reason why philosophy of medicine cannot exist, it does not. Just as Shaffer posed as a foil to force clarification of the notion of philosophy of medicine, so did Caplan. Caplan's assertion for the non-existence of philosophy of medicine depended on his definition of it: "The philosophy of medicine is the study of the epistemological, metaphysical and methodological dimensions of medicine; therapeutic and experimental; diagnostic, therapeutic, and palliative" (1992, p. 69). Given this definition, he maintained that philosophy of medicine is really a sub-field of philosophy of science. And its goal or focus should be epistemological rather than ethical.
Caplan (1992) discussed three possible responses to his thesis for the nonexistence of philosophy of medicine. The first is agreement both with his definition for the philosophy of medicine and with his conclusion that philosophy of medicine so defined does not exist. The second response is agreement with the nonexistence conclusion but disagreement over his definition for the philosophy of medicine. He recognized that his definition is narrow in scope and that some may want to expand it to include ethics. Caplan, however, contended that ethics is normative while philosophy need not be. The final response is acceptance of the definition but rejection of the non-existence conclusion. Caplan noted that those who make this objection often point to the published literature and professional meetings concerned with philosophy of medicine. Although he admitted the impressive nature of this evidence, it is, in principle, inadequate to defend the existence of philosophy of medicine.
According to Caplan, the philosophy of medicine does not exist because it does not meet the necessary criteria for recognition as a field or discipline. Caplan identified three criteria to define a field. The first is "a subject must be integrated into cognate areas of inquiry" (1992, p. 72). In other words, the discipline must cohere with other well defined disciplines. For Caplan, philosophy of medicine is more like an "intellectual island" on an otherwise coherent "intellectual map" of disciplines. Second, a discipline requires a "canon... a set of core readings, articles, books and case studies which are taught to those wishing to enter the field and cited by those who see themselves as working collegially in the field" (1992, p. 72). Caplan's claim was that philosophy of medicine lacks such a canon. Finally, "to be a field an inquiry ought to have certain problems, puzzles and intellectual challenges that define its boundaries" (Caplan, 1992, p. 73). Other than the notions of disease and health, philosophy of medicine fails this criterion as well.
Next, Caplan raised a challenging question: "So, if the philosophy of medicine does not meet the criteria that would confer disciplinary or sub-disciplinary status on the work that has gone on to date in its name, is that a bad thing?" (1992, p. 73). His answer was an emphatic "yes" for the following reasons. First, philosophy of science has too long ignored the applied branches of science that could breathe new life into stale answers to questions like theory development or evolution. Philosophy of medicine could assist in this endeavor. Second, a robust philosophy of medicine is sorely needed for bioethics. Finally, philosophy of medicine could contribute to the development of medicine itself in terms of clinical trial design or explicating notions of pain and suffering. Caplan concluded that "while there are no in principle reasons why the philosophy of medicine cannot exist, it does not yet exist" (1992, p. 74).
Henrik Wulff (1992) provided commentary on Caplan's article. He began by dividing participants at meetings on medicine and philosophy into three categories. The first consists of professional philosophers, who use medicine to do philosophy. The second consists of medical professionals who approach philosophy as a hobby and of professional philosophers who engage philosophical problems from a medical perspective. The last category consists of medical professionals who have formal training in philosophy and those who have no training in philosophy because of professional obligations.
According to Wulff, Caplan is a member of the first category and being a member of this group accounts for Caplan's denial of philosophy of medicine's existence. However, from a medical perspective philosophy of medicine-although not as robust as it should or could be-is a vital part of contemporary medical thinking, especially for medical professionals of the third category who are too busy in their practices to engage the medical problems from a philosophical perspective. In conclusion, Wulff beckoned professional philosophers of the second category to "come to my support and argue that philosophy of medicine does exist as a medical subdiscipline, if not as a philosophical one" (1992, p. 85).
In presaging responses to the thesis of the non-existence of philosophy of medicine, Caplan was certainly correct that the thesis would be challenged. However, only a few took exception to his definition for philosophy of medicine. Most of the debate focused on whether philosophy of medicine met the criteria necessary for defining a field or discipline, and only a few challenged whether the criteria themselves are met. For example, although Vic Velanovich (1994) agreed with Caplan's conclusion, he claimed that philosophy of medicine is a developing field of inquiry, in terms of John Dewey's notion of the logical development of a discipline.'
As for Caplan's first criterion, Velanovich admitted that much work remains to integrate philosophy of medicine into other disciplines. For the second criterion, he cited Jeffery Spike's article on teaching philosophy of medicine, which he noted Caplan also referenced, and Wilfried Lorenz's list of works on theoretical surgery, as providing a foundation for development of a canon. Finally, Velanovich listed a series of metaphysical, ontological, and epistemological questions, concerning medical causation, reductionism, and explanation, which he claimed provides critical problems and puzzles for philosophy of medicine. "I have argued," concluded Velanovich, "that [philosophy of medicine] should be considered a developing field which will eventually meet all the criteria Caplan imposes on any endeavor to be called such" (1994, p. 81).
Although Caplan's thesis for the non-existence for philosophy of medicine was critiqued mainly in terms of the criteria for establishing a discipline, his thesis was also criticized by a few with respect to his definition for philosophy of medicine. Some philosophers of medicine felt Caplan's definition was too narrow and wanted to broaden it. For example, Engelhardt and Kevin Wildes argued for an expanded conception of the philosophy of medicine. Although one could argue, pro Caplan, that philosophy of medicine engages no unique problems vis-n-vis philosophy of science or biology Engelhardt and Wildes held, contra Caplan, "there would still be merit in exploring the ways in which philosophical study and analysis can be directed to the understanding of medicine" (1995, p. 1683). Kenneth Schaffner and Engelhardt argued for an even broader conception for philosophy of medicine, "as encompassing those issues in epistemology, axiology, logic, methodology and metaphysics generated by or related to medicine" (1998, p. 264). They included not only the natural sciences but also the social sciences, e.g. George Engel's biopsychosocial model.
In response to the broad or expansive definition for the philosophy of medicine, Pellegrino insisted that such a definition "dilutes the specificity of philosophy of medicine and weakens the identification of a definite set of problems" (1998, p. 319). He then proposed a more narrow definition for philosophy of medicine as "a critical reflection on the matter of medicine-on the content, method, concepts and presuppositions peculiar to medicine as medicine" (Pellegrino, 1998, p. 325). The goal of this relationship is to understand medicine per se, i.e. the ultimate reality of what constitutes medicine beyond the entities that are studied in medicine. To that end, Pellegrino claimed that the philosophy of medicine requires a precise or narrow definition of medicine.
Although medicine depends on the natural sciences, according to Pellegrino, it is not simply a branch of them. Rather, medicine is concerned with more than obtaining truth but the truth applied specifically to the health of individuals and societies. Tantamount to that goal is the clinical encounter between physician and patient. "Philosophy of medicine," concluded Pellegrino, "is concerned with the phenomena peculiar to the human encounter with health, illness, disease, death, and the desire for prevention and healing" (1998, p. 327). The basis for philosophy of medicine is the telos of medicine: the caring of the physician for the patient's healing (Pellegrino, 1998).
Wildes (2001) responded to both Pellegrino and Caplan, charging them with failure to engage the broader social context in which medicine is practiced. Pellegrino's and Caplan's approaches were too narrow and myopically fixated on the essence of medicine, with Caplan's approach being too analytic, in terms of an applied science, and with Pellegrino's being too phenomenological, in terms of the patient-physician encounter. According to Wildes, the broader approach takes into consideration the social or cultural dimension of medicine: "medicine is a socially constructed set of practices and philosophy of medicine must take this social dimension into account if it is to be therapeutic in terms of medicine's current crisis]" (2001, p. 74). By social construction, he meant that medicine is practiced in a specific social or cultural context. After all, he argued, notions like health and disease are culturally laden. "For philosophy of medicine to scrutinize medical practice," concluded Wildes, "it too must take the social structures into account and not be too narrowly construed" (2001, p. 85).
Pellegrino (2001) responded to Wildes by defending an emphasis on the telos of medicine, as its distinguishing characteristic, in terms of patient-physician relationship as a realistic healing encounter. "Clearly, this relationship was not the whole of medicine," argued Pellegrino, "but it is still in my opinion that which makes it a distinct human activity" (2001, p. 171). In fact, a teleologically based philosophy of medicine is "the only tenable basis for an ethics of the healing professions as a whole in an era of widespread moral and social pluralism like ours" (Pellegrino, 2001, p. 173). Pellegrino admitted that he did not emphasize the primary importance of the social for defining the philosophy of medicine. His reason was that he follows an Aristotelian projection from the virtuous individual to the virtuous society. It is in this context that Pellegrino claimed he engages the social dimension of medical practice in his philosophy of medicine. For Pellegrino, Wildes' emphasis on the social construction of medicine resembles nominalism and "allows for no permanent theory of medicine and therefore allows no permanent or stable ethics of the profession" (2001, p. 177).
Recently, William Stempsey has offered a broader conception of the philosophy of medicine. "Philosophers of medicine today are addressing not only issues of medical ethics and the doctor-patient relationship," according to Stempsey, "but also models of medicine, visions of human nature, concepts of health and disease, conceptions of the body, epistemological standards of evidence and other topics" (2004, p. 246). He identified philosophy of medicine as a philosophical sub-discipline and situated it thusly with respect to three factors.
The first is one's metaphysical worldview used to divide up the world. For example, whether one holds to holism or reductionism profoundly affects one's medical knowledge and practice. Philosophy of medicine can certainly help to clarify the metaphysical foundations of medicine. The second factor is one's understanding of cognate disciplines. Stempsey acknowledged that the relationship between medicine and philosophy is historically an enriching one for both disciplines and that "even in the face of changing perspectives on the disciplines of philosophy and medicine, there have always been a philosophy lurking behind medical thought and practice" (2004, p. 248). The final factor is the perspective from which the disciplines are viewed. Stempsey noted that much of the controversy over the existence of philosophy of medicine stems from a myopic view of the disciplines: "We should not let narrow disciplinary boundaries blind us to the richness that is inherent in a broad view of the philosophy of medicine" (2004, p. 250). In conclusion, he beckoned for a "medical studies" discipline that incorporates historical, philosophical, and social dimensions of medical knowledge and practice.