Reductionism is a constitutive feature of the "standard view" or inherited conception in philosophy of science, such as Enrique Marí says in his book "Elements of comparative epistemology". Whereas the "standard view" is one of the articulators of scientism - epistemological hegemonic position in the contexts of education, innovation, evaluation and application of techno-scientific knowledge - imposed an analysis of this concept as a necessary condition for its overcoming. This article intends to define the meaning and scope of the epistemological reductionism within the framework of the biomedical sciences, on the basis of their genealogy, and then moving in the explicitation of the multiple ways that invest for, finally, realize the consequences of his naive acceptance - or perhaps downright accomplice, of a great part of the scientific community. The consequences are presented in the field of theory, but very particularly in the field of praxis. Establishing the ethical implications of the epistemological reductionism in the theory and practice of Biomedical Sciences is the objective of this work.