Kazem Sadegh-Zadeh (; ; 23 April 1942 – 6 March 2023) was a German analytic philosopher of medicine of Iranian descent. He was the first ever professor of philosophy of medicine at a German university and has made significant contributions to the philosophy, methodology, and logic of medicine since 1970.See a list of Sadegh-Zadeh's works on these subjects here
Life and career Sadegh-Zadeh was born on 23 April 1942 in Tabriz, Iran. The fourth of eight children, he grew up in Tabriz and attended school from 1947 to 1959. His father was a craftsman and manufacturer and ran a minor terrycloth weaving mill. In the wake of severe political and economic crisis in the country caused by the U.S. and British coup d'état against the democratically elected government of Iran's Prime Minister Mohammad Mosaddegh in 1953,CIA Confirms Role in 1953 Iran CoupCIA admits role in Iran coup he went bankrupt and never recovered. At eleven years of age when entering the high school shortly after his father's bankruptcy, Sadegh-Zadeh told his parents he would become a professor of medicine in the future and provoked laughter from them.Cf. Sadegh-Zadeh's autobiography Upon finishing school education at the prestigious Ferdowsi High School in Tabriz, Sadegh-Zadeh came to Germany in March 1960 to pursue his goal as a working student and studied medicine and philosophy at the universities of Münster, Berlin, and Göttingen from 1960 to 1971 with Internship and residency 1967–1971. He earned a doctorate of medicine, Dr. med., from the University of Göttingen in November 1971. But after these five years of doing practical medicine he left clinical practice to conduct theoretical research on clinical theory and reasoning, for during his work in the hospital he had got the impression that in the foundations of clinical decision-making something was going wrong to produce about 38% errors of diagnosis and treatment.Cf. Gross R, and Löffler M, Prinzipien der Medizin. Eine Übersicht ihrer Grundlagen und Methoden. Berlin: Springer, 1997, p. 357. In an autodidactic way he specialized in the philosophy of medicine and was assistant professor and lecturer 1972–1982 and full professor of philosophy of medicine 1982–2004 at the University of Münster located in the city of Münster in the state of North Rhine-Westphalia in northwest Germany. He was married since 1970 and has two sons.
Sadegh-Zadeh was the founder of analytic philosophy of medicine.Seising R, A "Goodbye to the Aristotelian Weltanschauung" and a "Handbook of Analytic Philosophy of Medicine". In: Seising R, Tabacchi ME (eds.), Fuzziness and Medicine: Philosophical Reflections and Application Systems in Health Care, A Companion Volume to Sadegh-Zadeh's Handbook of Analytic Philosophy of Medicine. Berlin: Springer, 2013, pp. 19–76.Seising R, A fuzzy structuralist view on the Analytic Philosophy of Medicine. In: IFSA World Congress and NAFIPS Annual Meeting (IFSA/NAFIPS), 2013 Joint, Edmonton, AB, 2013, pp. 114–121.Seising R, Fuzzy concepts and genetic epistemology. In: Seising R, Trillas E, and Kacprzyk J (eds.), Towards the Future of Fuzzy Logic. Berlin: Springer, 2015, pp. 357–376.Sadegh-Zadeh K. The organism as a cyclic-causal system. (In German.) Ärztekolloquium 1970; No. 1, pp. 26–39, edited by Duensing F. Department of Clinical Neurophysiology, University of Göttingen.Sadegh-Zadeh K, Handbook of Analytic Philosophy of Medicine. Second edition. Dordrecht / Holland: Springer, 2015. See the Handbook here He inaugurated this new direction in the philosophy of medicine, which he based, like analytic philosophy, on the application of formal logic to distinguish it from the traditional philosophy of medicine for he did not consider this latter, traditional style of philosophizing on medicine a scientific endeavor, but "belles lettres".See pp. 886–887 and footnote 35 on p. 180 of the aforementioned Handbook His international recognition came especially through his work on the logic and methodology of clinical reasoning, including artificial intelligence and fuzzy logic application in the theory of medical decision-making, in the theory of medical knowledge and in medical ethics. He was the founding editor of two international journals, first Metamed founded in 1977 (renamed Metamedicine later. Current title: Theoretical Medicine and Bioethics, published by Springer Verlag),See the journal's webpage here and second, Artificial Intelligence in Medicine founded in 1989 (published by Elsevier).See the journal's webpage here His extensive work includes the following innovative theories: a comprehensive theory of medicine presented in his monumental Handbook, theory of fuzzy biopolymers,Fuzzy genomes. Artificial Intelligence in Medicine, 2000; 18:1–28. In addition, an advanced version of the theory may be found in Section 17.5.4 on Fuzzy Logic in Biomedicine on pages 665–683 of the above-mentioned Handbook the prototype resemblance theory of disease,A PDF of the theory may be accessed here. In addition, see also the above-mentioned Handbook, pp. 165–212. the palimpsest theory of mind,See the paragraph A palimpsest theory of consciousness and self-consciousness in the above-mentioned Handbook, pp. 151–154. and the theory of technoevolution and .Sadegh-Zadeh K, When Man Forgot How to Think. The Emergence of Machina Sapiens. (In German.) Tecklenburg, Germany: Burgverlag, 2000.
Work Analytic philosophy of medicine Sadegh-Zadeh conceived analytic philosophy of medicine as philosophy of medicine in the analytic tradition of philosophizing, i.e., philosophy of medicine by means of logical and conceptual analysis with its primary fields of inquiry being:
Philosophy of medical language, Medical praxiology, i.e., philosophy, methodology and logic of medical practice, Medical epistemology, Medical deontics, i.e., analysis of medical morality, obligations, and law, Medical logic, and Medical metaphysics.Seising R, Tabacchi ME (eds.), Fuzziness and Medicine: Philosophical Reflections and Application Systems in Health Care, A Companion Volume to Sadegh-Zadeh's Handbook of Analytic Philosophy of Medicine. Berlin: Springer, 2013.
Philosophy of medical language Sadegh-Zadeh considered medical language an ill-structured and ill-kept extension of everyday language by adding technical terms such as "angina pectoris", "appendicitis", etc. Sadegh-Zadeh claims that most of its terms are imprecise and ambiguous because they are either undefined or ill-defined.Cf. Chapter 2 and page 822 of the above-mentioned Handbook. Since it has a significant impact both on medical knowledge and medical decision-making, he devotes himself extensively to the analysis of its nature and of its syntax, semantics, and pragmatics. He demonstrates and analyzes what he claims to be the inherent vagueness of medical terms and constructs techniques for dealing with this principally ineliminable feature by means of fuzzy logic. To this end, he introduces a comprehensive methodology of medical, including fuzzy, concept formation. Inspired by Patrick Suppes's and Carl Gustav Hempel's works,Suppes P, Introduction to Logic. New York: Van Nostrand Reinhold Company, 1957. Chapters 8 and 12.Hempel CG, Fundamentals of Concept Formation in Empirical Science. Chicago: The University of Chicago Press, 1952. he bases this methodology on an explication and formalization of all methods of definition known today.Cf. pp. 13–118, particularly 69–118, in the above-mentioned Handbook
Medical praxiology Medical, or clinical, praxiology is an old term introduced by Sadegh-Zadeh in 1977–1981 already to denote a wide-ranging inquiry into the foundations of clinical practice, particularly of clinical judgment and decision-making, with the aim of reducing diagnostic-therapeutic errors and of improving physician performance.Basic problems in the theory of clinical practice. Part I: Explication of the concept of medical diagnosis. Metamed, 1977;1:76–102.Foundations of clinical praxiology. Part I: The relativity of medical diagnosis. Metamedicine, 1981;2:183–196. See the article here In the latter article referred to, he has defined the term explicitly as "analysis of clinical practice", "inquiry into clinical practice", and "theory of clinical practice", i.e., the philosophy, methodology, and logic of medical doing and acting.Cf. page 121 in the above-mentioned Handbook. Central topics include everything related to concepts and theories that are basic to clinical practice, i.e., the concepts and theories of patient, suffering, health, illness, disease, diagnosis, etiology, prognosis, therapy, and prevention. This perspective, Sadegh-Zadeh claims, creates a fertile scientific field with a host of tasks ranging from conceptual analyses (like "what is disease?", "what is a diagnosis?", "what is differential diagnosis?", etc.) to logical analyses – such as "is clinical decision-making computable or does it require human intelligence and intuition?" – to epistemology, ethics, and metaphysics of clinical decision-making and so forth. Over the past decades, Sadegh-Zadeh's clinical praxiology has developed further with increasing sophistication. One example of his theories is the prototype resemblance theory of disease presenting a fuzzy-logical explication of the vague concept of disease:
Medical epistemology Medical epistemology is the philosophy of medical knowledge or simply theory of medical knowledge. Sadegh-Zadeh conceived it as a task or branch of the philosophy of medicine already in 1982 deploring that "The contemporary philosophy of medicine movement is mainly concerned with medical-ethical problems while unduly neglecting medical-epistemological ones".Cf. Sadegh-Zadeh K, Perception, illusion, and hallucination. Metamedicine, 1982; 3:159–191. See the article here
The category medical knowledge consists of statements of spatio-temporally localized facts, general hypotheses, and theories. Sadegh-Zadeh has proposed an elaborate systematics of all types of medical hypotheses and knowledge the latter ones including classificatory knowledge, causal knowledge, experimental knowledge, theoretical knowledge, practical knowledge, clinical knowledge, and medical metaknowledge.Cf. pp. 463–478 of the Handbook Most important among them is what is called practical knowledge or know-how in medicine. By a formally precise explication of this knowledge type he shows that medical-practical knowledge actually consists of conditional norms, i.e., deontic conditionals, mainly conditional obligations. This is one of the reasons why Sadegh-Zadeh considers medicine a deontic discipline. Specifically, he views clinical practice as practiced morality because clinical decision-making is nothing but the application of conditional obligations of which diagnostic-therapeutic rules of action primarily consist. And since clinical research pursues such rules of action and tries to improve the available ones, it constitutes explorative and normative ethics based on empirical research and experience.Sadegh-Zadeh K, Medicine as Ethics and Constructive Utopia. (In German.) Tecklenburg / Germany: Burgverlag, 1983. See also pp. 597–603 and 843–845 of the Handbook
A central role in Sadegh-Zadeh's medical epistemology play medical theories. He analyzes the concept of "medical theory" in line with the so-called structuralist view of theories to represent their structure and content, according to Patrick Suppes and Joseph D. Sneed's approach, as set-theoretic predicates. This enables him to show that a theory in medicine cannot be confirmed, supported, disconfirmed, verified or falsified simply because it is merely a conceptual structure and no epistemic entity to be true, probable or false. It does not make any empirical claims about the world. Such claims are made using the theory as a tool. The claims themselves, as empirical hypotheses, are something different than the theory.See pp. 417–461 of the Handbook