The question of how science, medicine and medical practice are related also compromises the crucial issue of the character of medicine. At the beginning of the 19th century, medicine tried to overcome the ancient contradiction within the unity of scientific thought and the deduction of guidelines and techniques for medical practice. This aim was partly achieved in medico-theoretical reasoning and practical procedures as well as for nosology, casuistic thinking and diagnostics. But medicine is a discipline directed towards healing. So the intentions of medicine and the reality of clinical healing possibilities, however, showed an increasing divergence since the middle of the 19th century. This divergence triggered considerable reactions not only from "Schulmedizin" and from other disciplines but also from practicing doctors and mainly from (disappointed) patients. Together with the continuous changes in empirical clinical research these internal and especially external reactions to medicine showed fundamental differences between medicine and the sciences. During the decades of this development it has become obvious that medicine will never become a pure science, not even an applied science. As medicine is concerned with patients who need to be considered as individual subjects, medical knowledge and medical practice consequently form a dialectic unity which is directed by the patient as a subject.
科学、医学与医疗实践如何相互关联的问题也涉及到医学本质这一关键问题。19世纪初,医学试图在科学思维的统一以及医学实践指导方针和技术的推导中克服古老的矛盾。这一目标在医学理论推理、实践程序以及疾病分类学、决疑思维和诊断方面部分得以实现。但医学是一门旨在治疗的学科。然而,自19世纪中叶以来,医学的意图与临床治疗可能性的现实之间的差异日益增大。这种差异不仅引发了“学院医学”和其他学科的强烈反应,也引发了执业医生尤其是(失望的)患者的强烈反应。随着经验性临床研究的不断变化,这些对医学的内部尤其是外部反应显示出医学与科学之间的根本差异。在这几十年的发展过程中,很明显医学永远不会成为一门纯粹的科学,甚至也不会成为一门应用科学。由于医学关注的是需要被视为个体主体的患者,医学知识和医学实践因此形成了一种以患者为主体的辩证统一。