正當防衛法理，源自於權利保護的構想，當遭受不法侵害，公權力又無法及時保護，防衛者在緊急狀況下，被動採取防衛行為，以避免權利遭受不法侵害。防衛是否過當，必先定位正當防衛的屬性，即被動性的行為及法律允許的行為，再依具體客觀事實，判斷是否符合正當事由，行為有無過當。本文認為判斷防衛過當標準，可審查以下三點：法益權衡是否適當、防衛的手段是否適當，以及最寬容原則判斷是否過當。倘若防衛保護的法益，以及使用手段，未高於不法侵害，則屬於正當行為，若高於不法侵害，則為防衛過當。當利益衡量的思考及防衛手段的衡量思考，皆無法通過審查標準，必須以最寬容原則，檢視防衛行為是否過當，當防衛行為「有」或「無」產生懷疑，依無罪推定原則例外，認定有此防衛行為，再依客觀中立的第三者審查，判斷防衛行為有無過當，若認為防衛行為合理、適當及必要，則屬於正當行為，若認為防衛行為非合理、適當及必要，則屬於防衛過當。
The legal theory of the right of self-defense originated from the concept of the protection of rights. When an individual is unlawfully infringed upon and unable to obtain timely protection by public power, he or she, being the defender, passively takes defensive action so as to avoid unlawful infringement under emergent circumstances. However, the determination of excessive self-defense requires to clarify the nature of such behavior be passive and legally granted and if such behavior meets the criteria of just cause based on concrete and objective facts. This study suggests that the following three perspectives can be referred to as the standards for the determination of excessive self-defense: the adequacy of balance of legal interest, the appropriateness of defensive measures and the application of the maximum tolerance principle. In the event that the levels of the legal interest of defensive protection and the defensive measures taken are not higher than that of unlawful infringement, self-defense is considered as proper behavior. On the other hand, if the above said levels are higher than that of unlawful infringement, that is excessive self-defense. When neither the consideration of the balance of interests nor the consideration of defensive means passes the censorship standard, the principle of maximum tolerance should be adopted to examine whether the behavior is excessively defensive. Either ＂any doubt＂ or ＂no doubt＂ arising from defensive behavior first leads to determining the occurrence of the defensive behavior in accordance with the exception of presumption of innocence. Next, a review shall be conducted by an impartial and neutral third party to determine whether the defensive behavior is excessive. When the defensive behavior is deemed to be reasonable, appropriate, and necessary by the third party, the behavior is determined as proper behavior. If defensive behavior is deemed unreasonable, inappropriate, and unnecessary, it is determined to be excessive self-defense.
