Thursday, July 27, 2017

John of St. Thomas on Modal Propositions

An interesting passage in John of St. Thomas's Outlines of Formal Logic:

And notice that every modal, if it is true, is a necessary proposition and has eternal truth because it applies the mode due the proposition's truth arising from an intrinsic connection. For example, if you said, For Peter to run is contingent, this is a necessary proposition itself, since contingency necessarily fits Peter's running. And from this you see how the First Cause is able to cause freedom and contingency in us while acting infallibly, because the First Cause not only causes the things themselves, but their modes also, and gives to each its own mode. And thus it does not follow from divine causality, for example, that Peter's walking is necessary; rather it is infallible and necessary that Peter's walking becomes so freely and contingently; for freedom and contingency fit this walking intrinsically and necessarily.

[John of St. Thomas, Outlines of Formal Logic, Wade, tr., Marquette University Press (Madison, WI: 1955) p. 94.] There are some interesting complexities, I think, with taking every true proposition with an alethically modal predicate to be necessarily true.