Based on the criticism of the Prussian legislators and the ruling class, which confounded the moral condemnation and the criminal liability, Feuerbach created the legal impossibility theory at the beginning of the seventeenth century. Soon afterwards Feuerbach’s legal impossibility theory was severely criticized by other criminal law scholars such as Escher and Tittmann who hold the point that law and morality can not be separated. Therefore, for centruries the subjective and objective theories contradict while coexist. In criminal jurisprudence of civil law systems, theories on legal impossibility is so intricate that subjective and objective theories contradict while coexist. Further, different interpretations of legal impossibility theory lead to arguments over its demarcations between crime and non-crime, punishment Issues and the relationship between superstition and incomplete attempt. Through the longitudinal studies and horizontal research about the legal impossibility theory, we can find that the legal impossibility meet the requirements of the constitution of crime, and the legal impossibility belongs to criminal attempt. What’s more, on the issue of punishment, The constitution of such punishment shall be adhere to the concrete dangerousness test, since its culpability for criminal liability lies in the combination of the intent to commit and performing the act which constitute the two basic elements of a crime then resulting in social harm to a great extent. Thus, different from relative legal impossibility, absolute legal impossibility(include superstition) should not be punished by criminal law anymore. As for the dangerousness test criteria, we should stand in an objective and scientific position first of all. In the next place, we should put our feet on others' shoes while we judge them according to the sociological laws . Keywords: legal impossibility; attempted crime; attempted crime due to impossibility

基於對嚴重混淆了道德上的譴責性與市民的可罰性的普魯士立法者與統治階級的批判，費爾巴哈于十九世紀初提出了不可罰的不能犯理論，開創了刑法上不能犯理論之先河。在埃舍爾、迪特曼等主張法與道德不可分離、不存在不可罰的不能犯的學者的否認與批判下，開啟了長達數個世紀的主客觀之爭。在主觀說與客觀說的基本對立下，各地對有關不能犯問題的研究與理解可謂是異常複雜，特別是在諸如“不能犯未遂的性質問題”、“不能犯未遂的處罰問題”、“不能犯未遂與迷信犯的關係問題”、“不能犯未遂的分類標準問題”等至關重要的問題上，仍然是眾說紛紜，存在著頗多的爭議及疑點。 通過對不能犯未遂性質之爭所進行的縱向的歷史分析研究以及對德國、日本等地不能犯理論進行的橫向的比較研究我們可以發現，不能犯未遂之行為人主觀上具備明確的犯意，且在該犯意的支配下著手實施了具體的實行行為，具有主客觀統一性，符合犯罪構成的基本要件，屬於犯罪未遂；在不能犯未遂的處罰問題上，應當對不能犯未遂合理區分為對刑法所保護之法益具有危險性的相對意義上的不能犯未遂以及對刑法所保護之法益不具有危險性的絕對意義上的不能犯未遂。對於相對意義上的不能犯未遂可以因其對刑法所保護之法益構成了威脅而對其科以刑罰，而對於絕對意義上之不能犯未遂可在認定其在性質上屬於犯罪未遂后因其對法益不具有危險性而不再進行處罰；在迷信犯和不能犯未遂之關係問題上，迷信犯符合犯罪的構成要件屬於絕對不能犯未遂，只是因為其對法益不具有任何危險而不再予以處罰；在對不能犯未遂是否具有危險性進行評判時，要在一行為發生后，在事後通過已經被社會公眾所能夠普遍認知與接受的科學規律與日常經驗法則，考慮到事發當時的場地、環境、時間等具體的因素，從公正、中立的普羅大眾的立場出發去設身處地地對有無危險性進行事後的、客觀的、全面的綜合判斷。在此基礎上，對刑法所保護之法益不具有危險性的，認定為絕對不能犯未遂，對刑法所保護之法益具有危險性的，對之認定為相對不能犯未遂。 關鍵字：不能犯，不能犯未遂，未遂犯