摘要： 法教义学在中国法学界受到社科法学的批评乃至抨击，实则属于法律自治性危机的一种体现。法教义学的现有文献，并没有对法教义学的核心即规范问题进行充分的外部观察。系统理论直面法律的悖论，将法律的语义放到社会理论之中进行观察，对探寻法教义学在现代功能分化社会中的困境和出路具有重要的理论意涵。系统理论关注法律规范本身，从法律概念的自我指涉性、法律功能的规范期望属性以及法律开放与封闭的共生角度，从外部解读了法教义学，并回应了当下法教义学在法律论证中面临的困境。系统理论的区分、再入、冗余、结构耦合等概念，均围绕法律规范的外部观察进行构建，对法律自治问题和法教义学的现代图景形成了不同于以往文献的论述，可以为这场学术争论提供有益的智识资源。

关键词: 系统理论, 卢曼, 法教义学, 法律自治, 二阶观察

Abstract: When legal dogmatics faces the critiques from the studies of law and social science, it represents the crisis of legal autonomy in fact.The current literatures on legal dogmactics have not sufficiently observed the problem of normativity which is the central problem of legal dogmatics from the perspective of external observation.The systems theory faces the paradox of law and observes the legal semantics in social theory.Thus, it has important theoretical contribution to the dilemma and path of legal dogmatics in modern functionally differentiated society. Systems theory concerns about the legal norm itself and starts with the selfreferentiality of legal concepts, the normative expectation of legal function, and the co-existence of law's openness and closure, through which it analyses the legal dogmatics from the outside and responses the dilemma in legal argumentation of the legal dogmatics. The concepts of distinction, re-entry, redundancy, and structural coupling are all constructed from the perspective of external observers of the legal norms. Systems theory formulates new arguments of legal autonomy and legal dogmatics that are different from previous literatures, and it can add new knowledge to this theoretical dispute.

Key words: Systems Theory, Niklas Luhmann, Legal Dogmatics, Legal Autonomy, Second-order Observation