Clinical thinking is one of the core competencies that clinical physicians must possess. To cultivate this ability well, this book proposes an original theory named "Causal Clinical Thinking."

The book elaborates on the foundational basis of this original theory, the "Objective Causal Law of the Human Body" (OCLHB), which is derived from the biological core principle "structure determines function." OCLHB is expressed as "human body structure → (determines) human body function → (manifests) human body state," with individual expressions for healthy individuals and patients.

For clinical thinking, based on the OCLHB, the logical model of clinical diagnosis is abductive reasoning from the result (disease state) to the cause (structural lesions, functional changes). This model clarifies the interpretation of clinical information, providing a clear and structured thinking paradigm for junior physicians. It also effectively integrates knowledge from various basic disciplines, as well as basic and clinical knowledge, thereby enhancing the logic, accuracy, and efficiency of diagnosis and improving the teaching outcomes of clinical thinking.

The innovation of this book in the field of Clinical Decision Support System (CDSS) lies in the following aspects:

· Starting from the perspective of clinical thinking, it shifts the foundation of CDSS construction from data association based on probability theory to medical causal logic, establishing a systematic and logically coherent guiding theory.

· On the medical theory based CDSS is easy for clinicians to understand and accept, and R&D costs can be reduced which is beneficial for the promotion of CDSS.

· The OCLHB establishes a clinical decision-making reasoning model with objectivity and causality. The objectivity gives the model universal applicability cross-departments, while the causality ensures the good interpretability of the reasoning process based on this model.

· This book not only theoretically unifies " interpretability " and "universal" within a unified systematic framework for the first time, but also provides feasible paths and medical theoretical foundations for the subsequent development of interpretable & universal CDSS, making it a pioneering work in this field.