The open theism debates may have cooled down a while back, but inquiring about divine foreknowledge still leads us into some weighty issues in the field of theology proper, issues of the perennially significant sort when it comes to the church’s understanding of God and his relationship to the world and its human inhabitants. In light of this, I thought it might be worth unpacking and discussing Aquinas’ article in the Summa which asks “whether the knowledge of God is of future contingent things” (Ia.14.13).
Under this article there are three potential objections against the claim that God’s knowledge includes future contingent things. Objection one judges that, since 1) the knowledge of God is the cause of all things known (see Ia.14.8) and 2) the knowledge of God is necessary with respect to things known, the necessary cause (God’s knowledge) must yield a necessary effect (the thing known), rendering future things not contingent but necessary. Objection two declares this proposition to be true: “If God knew that this thing will be, it will be.” However, the antecedent here is eternal and signified as past and, therefore, necessary, meaning that its consequent (the being of a thing known) also is necessary. Objection three reasons from the dynamics of human knowledge to the dynamics of divine knowledge: “even what we ourselves know must necessarily be…and, of course, the knowledge of God is much more certain than ours.” In short, if something is known, it must necessarily be. The conclusion, then, is that God knows no future contingent thing. This has the feel of an analytic statement: divine knowledge by definition cannot have as its object any future contingent thing. It’s interesting to note that the objections seem generally to affirm God’s knowledge of future things but question their contingency, whereas the open theists seem generally to affirm the contingency of future things but question God’s knowledge of these.
What has Aquinas to say in response? He contradicts the objections by quoting Psalm 32:15 as testimony to God’s knowledge of all the works of human beings. But, inasmuch as our works are subject to the freedom of our will, they are contingent. Thus, with the help of a fairly modest inference, Aquinas is able to draw from Old Testament Scripture to maintain that God does indeed have knowledge of future contingent things. From here Aquinas answers that God’s knowledge includes things actual and possible and, since some of these are future and contingent to us, God enjoys knowledge of future contingent things.