Explanation and essence in Posterior Analytics II 16-17

Breno Andrade Zuppolini

doi:10.14195/1984-249x_24_8

Abstract

In Posterior Analytics II 16-17, Aristotle seems to claim that there cannot be more than one explanans of the same scientific explanandum . However, this seems to be true only for “primary-universal” demonstrations, in which the major term belongs to the minor “in itself” and the middle term is coextensive with the extremes. If so, several explananda we would like to admit as truly scientific would be out of the scope of an Aristotelian science. The secondary literature has identified a second problem in II 16-17: the middle term of a demonstration is sometimes taken as the definition of the minor term (the subject), other times as the definition (or the causal part of the definition) of the major (the demonstrable attribute). I shall argue that Aristotle’s solution to the first problem involves showing that certain problematic attributes, which appear to admit more than one explanation, actually fall into the privileged scenario of primary-universal demonstrations. In addition, his solution suggests a conciliatory way-out to our second problem (or so I shall argue): the existence of an attribute as a definable unity depends on its subject having the essence it has, which suggests that both the essence of subjects and the essence of demonstrable attributes can play explanatory roles in demonstrations.

Highlights

Ἀrchαί 24 | Sep.-Dec. 2018 middle term of a demonstration is sometimes taken as the definition of the minor term, other times as the definition of the major
His solution suggests a conciliatory way-out to our second problem: the existence of an attribute as a definable unity depends on its subject having the essence it has, which suggests that both the essence of subjects and the essence of demonstrable attributes can play explanatory roles in demonstrations
With helpful examples, what kind of syllogism can be taken as a full-fledged demonstration – i.e. a demonstration of the “primary universal” – and what kind of explanatory role definitions play in demonstrative arguments

Summary

Two Questions and the Uniqueness Requirement

Aristotle begins APo II 16 interested in knowing whether every “occurrence” of an attribute – the verb used is “ὑπάρχειν” – that can be scientifically explained involves the occurrence of its putative explanatory factor (APo II 16, 98a35-36). In APo II 16, 98b2-4, a second question, apparently less controversial, is added It concerns sufficient causality as it is usually conceived: given a certain cause, does its effect follow?. If affirmative answers are given to both questions, there will be a mutual entailment between explanans and explanandum: given a certain cause, its effect follows (affirmative answer to Q2) and, given a certain effect, its putative explanation occurs as well (affirmative answer to Q1).. The use of “ὑπάρχειν” without a dative in 98a35-b4 may suggest that, for Aristotle, causation (or “being explanatory of”) is a relation that takes place between events or processes. In 98a35-b24, for instance, the philosopher is concerned with the following difficulty: do affirmative answers to Q1 and Q2 entail that “being explanatory of” is a symmetrical relation? If Q1 and Q2 are answered affirmatively, one could formulate the following two syllogisms (98b5-16):

Syllogism II

Syllogism IV

Syllogism VI

Extinction of fire holds of clouds