不純正不作為犯與作為其核心架構的「保證人地位」與刑法作為義務，長久以來是困擾德國與我國刑事法研究的深度議題，並是諸多學界重要見解發揮其精微論理的場域。然而，直至本文撰寫的今日而言，對於不純正不作為犯的研究雖已累積近百年的光陰，卻仍然難以跳脫循環論證、缺乏法理基礎的懷疑。 本文立基於我國與德國學說見解長久以來的偉大基礎，先行確認至今為止的所有議題討論都無法達到成功解決問題的高度後，嘗試以最直接的方式給予不純正不作為犯的刑法作為義務最為實際、具有共識的法理基礎，並借用於刑事法較少受到討論的「法律經濟分析」，將刑法作為義務作為一種社會制度的經濟特徵逐一抽出，並建構適合該種制度創造與存在的社會模型，最終就不純正不作為犯的刑法作為義務為何存在、如何存在得出基本假設，並就該種制度給予特定人民積極保護法益的義務，提出具有實際意義、成本合理分配的假設。 為檢驗本文透過個人與社會實際需求所進行之假設是否符合現代社會之實際需求，本文假設刑事法學界所承認之刑法作為義務與保證人地位，若多數吸納原屬於其他社會制度之人際關係，則多數刑法作為義務態樣之原型，應全部得透過本文回溯社會群體、個人需求的最初假設，而得出符合本文觀察之解釋。最後，於本文第四章之結論中，確實得出與本文理想圖像相契合之論證結論。申言之，當代諸多被刑法作為義務吸納之保證人地位，多數均存在本文所稱作為義務人得自履行救助義務直接得利之特徵，而使本文第三章所提之觀察與假設，有其實際論證基礎。至於無法透過本文假設所詮釋之保證人地位，如「危險前行為」、「自願承擔義務」，本文亦指出其法理基礎乃源自於第二章已提及不可論證之先驗性思考，而有斟酌其適當性之必要。 / Germany and Taiwan’s criminal law researching have long troubled derivative Omission Offences with its core “Criminal duty of care”. Until today, the study of derivative Omission Offences has been a hundred years, yet it is still difficult to solve the problem of circular argument and lacking of basis. Based on the great foundation of our country and the German doctrine, this paper has confirmed that the all the discussion so far has failed to achieve the goal of solving the problem successfully. This article tries to give the “Criminal duty of care” the most practical and consistent legal basis through the most direct way, by using “Economic Analysis of law” as Legal method. When we regard criminal law as an obligation as a social system, there are several economic features that can be used to answer our questions. Finally, we have the assumption that why Derivative Omission Offences exists and how it works, and this is a hypothesis that is of practical significance and takes into account cost allocation. In order to test whether our hypothesis is consistent with the current situation, this article one by one to dismantle the existing “state of protection”, and confirm that all “state of protection” are in line with our assumptions. In other words, all the obligors who choose through “Criminal duty of care” are to allocate the cost of fulfilling the obligation to protect. As for the “Criminal duty of care” does not meet the assumptions of this hypothesis, such as the creation of dangerous pre-behavior, voluntary commitment, this article also successfully demonstrated why they can not fit, and they are a lack of basic theory.

(in English): In this thesis I focus on the system of social protection in Japan at the turn of the 21st century and the role of the state in this system. In the first chapter I define the terms society, social policy and welfare state. The second chapter is dedicated to the historical development of the social policy from antiquity to the end of the Second World War. In the next chapter I concern myself with the character of the social protection system in Japan at the beginning of the third millennium, the changes in the Japanese society and the financial state of the social protection system. In the last chapter I analyse the reforms that have been done since the beginning of the new century and which propose was to stabilize the system of the social protection in Japan and make it sustainable.