Background and Purpose: A paradigmatic reading of medical history results in comprehending the evolution of main concepts based on different paradigms after provoked crises and scientific revolutions in the history of medicine. Basic concepts may fundamentally change in scientific revolutions, i.e., the routine image of phenomena changes in a Gestalt manner. According to modern medicine in the recent century, basic concepts, including causation and explanation, body and physicality, and disease and health have fundamentally changed in the history of medicine. The current study aimed to present and discuss a philosophical image of conceptual incommensurability in the causality concept for emphasizing examples of defining health and disease in different medical paradigms and some models in the scientific revolution of medicine. 

Materials and Methods: A philosophical analysis was applied to examine the philosophical foundations of medical paradigms. Searching in medical history helps perceive examples of understanding causation and its function. Moreover, both paradigms are discussed in more detail based on a comparative approach with examples.

Results: According to the incommensurability concepts in the science paradigms, simultaneous understanding of the causality concept is considered impossible in traditional-Iranian and modern medicine, i.e., evidence-based medicine.

Conclusion: This study emphasizes the independence of theoretical aspects and practical dimensions of medical paradigms and also deems dialogue and even methodical comparison between paradigms possible, and even necessary; however, this comparison is not a simultaneous communication between both paradigms and demands avoiding methodological confusion.