論証と原因

アリストテレス『分析論後書』第２巻第11章を手がかりに

抄録

Aristotle’s APo. claims that scientific knowledge requires a cause serving as the middle term in the demonstration. APo. II 11 considers how the well-known “four causes” should be understood in the theory of demonstration. What is key is the relation of the final cause to the other three causes. This paper discusses how the theory of demonstration handles these causes by considering their status and interrelation.

Aristotle examines the four causes from the perspective of the major and minor terms in a demonstration. The grounding cause states the essence of the minor term, and the essential and efficient causes state the essence of the major term. However, there are difficulties in considering the final cause. For, in the example of being healthy, illustrating the final cause involves two demonstrations. In the first demonstration, the middle term (food not staying on the surface) explains the essence of the major term (being healthy). In the second demonstration, however, the middle term (being healthy) does not explain the essence of the major term (food not staying on the surface) or the minor term (walking after dinner). In order to answer this problem, we have to mention two points: First, the final cause appears last in generation but arises first as the initial point of the explanation; secondly, the final cause explains the processes to the end as for the end. By considering these facts, I show that the second demonstration explains the major term and the minor term by the middle term from the viewpoint of temporal order that the first demonstration establishes.

This paper argues that APo. II 11 divides the four causes into the final cause and the other three causes and claims that the second demonstration includes “hypothetical necessity”. Consequently, this paper shows that Aristotle aims to exclude chance from a demonstration having the final cause as the middle term by introducing hypothetical necessity.