法官依法裁判（具體來說，指依法律與法進行裁判），是一項重要的德國憲法誡命，也成為德國法學方法論的制度背景與重要的問題意識。本文將透過問題史的研究方法，探討德國法學方法論如何處理法官依法裁判所帶來的疑難。本文將指出，法官依法裁判的誡命，在十九世紀末德國統一後出現，成為德國法官所應遵循的重要法律誡命。但此誡命出現後，德國法學方法論就反思到單憑法律難以提供法官判決所需的所有規範論證依據，因此產生了許多的解決之道。自由法學與利益法學在十九世紀末到威瑪共和時期，提出解決法律漏洞的方式。到了基本法時代，價值法學提出以法原則建立起來的內在體系，成為法官解釋與填補漏洞的依據。但價值法學的思維受到許多挑戰，不少學者認為，單憑法學方法論提出的觀點與方法規則，無法落實法官受法律與法拘束的憲法誡命，進而提出許多其他的方式來協助落實此一誡命。這些討論都強調法官受拘束與法官自主相互對立，為了達成法官受法拘束的要求，必須犧牲法官自主空間。但這樣又可能造成法官無法依個案需要，追求個案正義或適應社會變遷之結果。純粹法學與框架導向理論試圖克服此一對立帶來的二律背反。本文最後簡單說明此一問題史反思所指出的德國法學思維特性。

This paper tries to use the method of history of problems, to analyze the development of Germany legal methodology. This paper will point out that the commandment of "the Decisions of judge should accord to the law" appeared after the reunification of Germany at the end of the nineteenth century and became an important legal commandment for German judges to obey. However, after the appearance of this commandment, the German methodology of legal science has reflected on the fact that it is difficult to provide all the normative arguments required by the judicial judgment by the legal codes alone which enacted by parliament, therefore the scholars of the methodology of legal science developed many methods, to provide the legal arguments for the judicial decisions. They all noticed that the judicial decisions should on the one hand obey the law, on the other hand, the judge should also in necessary condition fill the gap of legal code to apply the law. These two commandments can't be so easily harmoniously achieved. The free law movement, the jurisprudence of interest, the jurisprudence of value, and many other thinking in the methodology of legal science developed various methods in the different historical and constitutional conditions to solute this problem. Besides, many scholars believe that it is impossible to accomplish the constitutional commandment that judges are bound by the law based solely on the methodological rules. Therefore, they proposed many other ways to help the judge in the case to achieve this commandment. These discussions presume that the restraint of judges and the autonomy of judges are opposed to each other. For achieving the requirement that judges be bound by the law, the space of judges' autonomy must be eliminated. Pure jurisprudence and framed order theory attempt to overcome the antinomy. These two theories try to prove that the autonomy of judge can be consistent with the constitutional commandment that judges are bound by the law. In the end, this paper briefly explains the characteristics of German legal thinking.