自從號稱先天存在之理性與「法」遭受實證主義者秉持科學實證方法所質疑以來，法實證主義放棄將法學的理性基礎架構在任何實質層面上，取而代之者，即是所謂「形式理性」－邏輯。法實證主義者一方面將法學架構在邏輯上；另一方面則宣稱邏輯具理性、完美與符合事實真實性，從而建立起法實證主義法學的客觀合理與普世性基礎。法實證主義的影響，從今日的法學教育即可得知，整個法學教育幾全環繞在法實證主義的主張之下，而法律也一直以來被視為是「理性」的代表與產物。正當法實證主義者與多數法律人沉迷於一己所號稱的理性世界之中，卻鮮有人驚覺愛因斯坦的相對論正開始其烈火燎原之舉－從自然科學界蔓延至人文、社會科學界。一場震撼舊知識的理性基礎革命，早已登場，而此正反映在西方後現代主義與新啟蒙運動之中。邏輯學之三段論法即是法實證主義者聲稱法學符合理性的根據。這一個遠可追溯至亞里斯多德的三段論法，仍是架構在西方自古希臘以來的本體論的思想上，而正是此依本體論的思維，使遭受法實證主義打擊之法哲學能夠宣稱，法實證主義之思維仍具法哲學的思維特徵。而也正是因為本體論，使類型學主宰法學界－甚至人文、社會科學界－一段甚久時日。然而這所有一切卻因愛因斯坦的相對論而遭受到質疑的命運。本文即以相對論為基礎，探討存在於三段論法中之問題點。藉由科學性的反省與批判，本文揭示三段論法的理性基礎的不完整性，進而動搖法實證主義之理性基礎，以表明為何在西方已將法實證主義宣告死刑之因。

Since the claimed inherently existing rationality and law have been challenged by the Positivists with its scientific empirical approach, Legal Positivism abstained from establishing a foundation for the science of law on any essential aspects; instead they established it based on ＂formal rationality＂, which is Logic. Legal Positivists framed the science of law through Logic on the one hand, and on the other they claimed that Logic is endowed with rationality that is beyond reproach and conforms to factuality; hence they established the objective rational and universal foundation of the Legal Positivist's science of law. From observing the current legal educational system, we can easily acknowledge the influence from Legal Positivism and the current legal educational system is embued with its position; therefore law is always treated under the rubric of rationality and its applied outcome. As Legal Positivists and most jurists are addicted to this claimed rational world, people seldom think in terms of Einstein's Relativity theory, which is just like a raging fire that has the potential to set the prairie ablaze. His theory has been extended from the field of the pure sciences to the human and social sciences. A revolution that convulses the foundation of the rationality of past knowledge has already come upon us, and it is also reflected in the trends of Western Postmodernism and the Neo-Enlightenment movement. Legal Positivists claim that the syllogism of Logic is the basis of legal science and that it is also confined within rationality. The syllogism of Logic can be traced back to Aristotle's Syllogism and it is still framed on the ground of Western Ontological thought that has its origins in the Ancient Greek era. In relying exclusively on the Ontological perspective, even though Legal Philosophy (the Philosophy of Law) is subject to Legal Positivism's critique, proponents can also claim that Legal Positivism still retains the characteristics of the thought of Legal Philosophy. Legal Positivism not only is based on the Ontological perspective, but it caused the Typology to dominate the field of the science of law, as well as the disciplines within the human and social sciences for quite a long time. However, all of this will eventually come to grips with the unavoidable destiny in the form of Einstein's Relativity theory. This article is based on a relativitivistic view which is employed to discuss several issues of Syllogism. Throughout the scientific introspections and critiques herein presented, this article attempts to reveal the insufficiency of the rational basis of Syllogism in order to shatter the rational foundation of Legal Positivism and also explain the reason why Legal Positivism has already been handed down its ＂death sentence＂.