Reductionism is a method of explanation that presupposes that the functioning of complex phenomena is reducible to the relationship of their simplest, most fundamental constituents. This practice is used in one form or another in almost all fields of science: physics, chemistry, ecology, sociology, medical sciences, etc. Reducing complex systems to the mechanisms of their parts is risky: it neglects the properties that can emerge from the analysis. system as a whole. These emergent properties may be unpredictable, unnecessary, or unprecedented and, therefore, must be observed by higher levels of the organization. There are several terms used to describe “anti-reductionism,” which is the belief that the whole is greater than the sum or its parts. To remain consistent, I will stick to the term “holism” to represent this theory of explanation. I will examine the expositions of various philosophers describing the use of reductionism in medicine: James A. Marcum explores the uses of reductionism and organicism (holism) in cancer research; Elisabeth A. Lloyd discusses socioeconomic aspects of human health; and Alfred I. Tauber explains the vital importance of holism in medicine. I will conclude with the belief that the integration of holism and reductionism, together, create the most ethically sound approach in medicine based on the epistemological challenges of reductionism in life sciences and medicine, as well as the moral imperative that requires a holistic approach to understand the functioning of human beings. James Marcum (2005) uses cancer research as a model to see the importance of metaphysical assumptions in guiding scientific studies. When one begins to study the profound complexity of biological systems and processes, ... half of the article ... effectively provide the necessary bridge between the knowledge obtained from reductionist and holistic studies to achieve the best possible medical treatment (Marcum, 2005). Works Cited Lloyd, Elsabeth A. “Reductionism in Medicine: Social Aspects of Health.” Promises and limits of reductionism in biomedical sciences. Eds. Van Regenmortel, Marc H. and David L. Hull. Chichester, West Sussex, England: John Wiley & Sons, 2002. Print.Marcum, J.A. “Metaphysical Assumptions and Scientific Practices: Reductionism and Organicism in Cancer Research.” International Studies in Philosophy of Science 19.1 (2005): 31-45. Print.Tauber, Alfred I. “The Ethical Imperative of Holism in Medicine.” Promises and limits of reductionism in biomedical sciences. Eds. Van Regenmortel, Marc H. and David L. Hull. Chichester, West Sussex, England: John Wiley & Sons, 2002. Print.