Book excerpt: Medical practice is practiced morality, and clinical research belongs to normative ethics. The present book elucidates and advances this thesis by: 1. analyzing the structure of medical language, knowledge, and theories; 2. inquiring into the foundations of the clinical encounter; 3. introducing the logic and methodology of clinical decision-making, including artificial intelligence in medicine; 4. suggesting comprehensive theories of organism, life, and psyche; of health, illness, and disease; of etiology, diagnosis, prognosis, prevention, and therapy; and 5. investigating the moral and metaphysical issues central to medical practice and research. Many systems of (classical, modal, non-classical, probability, and fuzzy) logic are introduced and applied. Fuzzy medical deontics, fuzzy medical ontology, fuzzy medical concept formation, fuzzy medical decision-making and biomedicine and many other techniques of fuzzification in medicine are introduced for the first time.