The logic of essentially ordered causes.
R. G. Wengert · Notre Dame Journal of Formal Logic · 1971
I In an article in the Philosophical Review of 1966, Patterson Brown set out to clarify one of the medieval proofs for the existence of God. 1 The argument with which he concerned himself can be referred to as the argument from essentially ordered causes; two main proponents of it are Aquinas and Scotus.Aquinas and Scotus, borrowing from Avicenna and Aristotle, say that causes may be ordered in two ways: essentially or accidentally.As a case of essentially ordered causes the medievals typically gave the example of a man pushing a stone with a stick.Accidentally ordered causes were continually exemplified by a father begetting a son, who in turn begets a son.These two examples will serve for discussing the three differences which Scotus proposes between essentially and accidentally ordered causes:(1) In essentially ordered causes, according to Scotus, the second depends on the first precisely in the act of causation.This is not so in accidentally ordered causes.(2) In essentially ordered causes, there is causality of another nature or order, since the higher is more perfect.This is not so among accidentally ordered causes.(3) All essentially ordered causes are simultaneously required to cause the effect; accidentally ordered causes can be successive.In terms of the two examples the differences are as follows: First, in the very act of pushing a stone the stick depends on the man to cause it to push; but while it is true that Isaac depends on Abraham for his existence, he requires no direct help from Abraham in begetting Jacob.The second difference is clear; for if we were asked in regard to the first example, which of the causes was more important, we should unhesitatingly choose the man who pushed the stick over the stick which was pushed by the man.Abraham and Isaac, however, are both fathers; neither is a superior type or kind of cause.Finally, the third difference is present in the examples, according to the medievals, because at the very moment the stick pushes, the man pushes with the stick.But it is obvious that Isaac does not beget Jacob at the very moment Abraham begets Isaac.