民事因果關係邏輯性序說

An Overview on Logics in Causation Reasoning

吳志正(Chih-Cheng Wu)

《臺大法學論叢》 36卷3期 (2007/09) Pp. 385-464

https://doi.org/10.6199/NTULJ.2007.36.03.05

摘要

探討因果關係理論的國內外法學論述已經相當豐富，惟本文認爲此揭論述之共同缺失在於－輕忽邏輯因果律之功能與重要性。由於學說與實務見解長期輕忽的結果，至今仍視「(必要)條件關係」即爲邏輯因果律之全部，導致因果關係之邏輯論證，往往因爲欠缺「充分條件關係」、「連言式條件關係」與「選言式條件關係」等推理，而有結構上嚴重之缺陷，進而造成實務上因果關係操作之空洞化，於個案的判斷上顯得很不邏輯。 觀察因果關係理論之晚近發展，雖令人目不暇給，但永遠不變的景像是，一方面持續表示對邏輯因果律之輕蔑與絕望，另一方面卻層出不窮地提出，不應屬於因果關係層次之各種歸責理論，作爲填補因果關係論證結構上缺陷的手段，某種程度上的確也解決了若干問題，但飲鴆止渴之後，因果關係的空洞化依舊，困惑只怕更多。 在非難邏輯因果律之同時，捫心自問，吾人對其基本推理原則已經全盤了解？還是依然故步自封於「（必要）條件關係」之刻板印象內而不識邏輯的阡陌縱橫？筆者憂心，倘吾人不知正視並圖修正過去對邏輯因果律長期的誤解，因果關係理論之未來發展，恐將如同Von Kries氏提出的「馬車走偏遇雷」名案一般，由於馬車夫的持續酣睡，使因果關係偏離發現真實之路，漸行漸遠。欲修補此因果關係論證之結構性缺失，吾人除了加強對邏輯因果律之瞭解外，實別無他法。本文即虛心地試著重新認識邏輯因果律之各項推理原則，並藉由演練民事法實務案例，熟悉各項因果律命題之基本操作，以期精緻化此長期遭忽視之邏輯因果律，重新定位其於因果關係判斷上之功能與重要性。

關鍵字

因果關係 ； 邏輯 ； 因果律 ； 歸責理論 ； 必要條件 ； 充分條件 ； 充要條件 ； 連言式命題 ； 選言式命題

並列摘要

A great deal of effort has been devoted to the topic ”causation” in the heavily piled legal literature only to achieve very limited success totally disproportional to the numerous volumes accumulated. The bifurcated approach to problems of causation has gained worldwide popularity, which leads to a two-phased inquiry, namely, in common law terminology, cause-in-fact and legal cause stage respectively. However, there always has been fatal defect in their causation reasoning since they exclusively restricted themselves to the logical ”essential condition” part by referring to the ”but-for” test or ”condition sine qua non” dictum as the cause-in-fact stage of inquiry, without properly paying due attention to other logical condition components such as ”sufficient condition”, ”conjunctive condition” and ”disjunctive condition”…etc. in their reasoning. Consequently, the normative labeling of the cause-in-fact stage of inquiry as ”causative” or ”factual” is actually neither factual nor logically causative at all.
This article attempted to elucidate systemically the fundamental logic regulations and illustrate the way they are manipulated in causation reasoning, with special emphasis on the missing condition components described above. Hopefully this overview will help to clarify the causation problems especially in the cause-in-fact stage of inquiry, and offer great aids in the pursuit of instinct nature of causation: ”objectiveness” and ”truth”, in stead of the historically theoretical preoccupation of scholars and judges dictated by common sense and equity.

並列關鍵字

Causation ； Logics ； Essential Condition ； Sufficient Condition ； Conjunctive Condition ； Disjunctive Condition

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