By Schubert Ogden
On an adequate theory of modality, according to which possibility in principle is ontological as well as logical, "real" and "logical" possibility are correlative, every real possibility being also a logical possibility-and vice versa.
But there remains the important distinction between being possible merely in principle and being possible also in fact. Why not express this distinction by further distinguishing "ontological possibility" from "ontic possibility"?
Then one may say that, although any logical possibility is also an ontological possibility (and vice versa), not every ontological possibility (and, therefore, logical possibility) is also an ontic possibility. Why not? Because whereas x is a logical possibility if, and only if, it makes coherent sense, and is an ontological possibility if, and only if, its actuality is compatible with the nature of concrescence as such, as indispensably referred to by anything that does make coherent sense, x is an ontic possibility if, and only if, certain ontic, or factual, conditions necessary to its actuality make it so.
Thus I understand:
by "logical possibility," "anything that makes coherent sense";
by "outological possibility," "anything whose actuality is compatible with the nature of concrescence as such, as the indispensable referent of all coherent meaning"; and by "ontic possibility," "anything whose actuality is made possible by certain ontic, or factual, conditions that are not only possible but actual."
20 August 2003; rev. 4 April 2009