I am continuing to read volume four of Muller’s immensely important work, Post-Reformation Reformed Dogmatics. Volume four deals with the Trinity. I came across this incredibly insightful and devastating analysis of Socinian theology (known today as Open Theism). Muller is talking about the definition of Person when it comes to the doctrine of the Trinity. The definition of Person has always been a description of one of the three subsistences within the Trinity. The Socinians objected to this, equating Person with Essence, such that if there was one essence, then there had to be only one Person.
As for the Socinian objection that a single essence implies a single person, Owen responds, “that in one essence there can be but one person may be true where the substance is finite and limited, but hath no place in that which is infinite.” This latter point is significant to the Socinian definition, inasmuch as the Socinian doctrine of God assumed a limited God… (Muller, PRRD IV, pg. 179)
Carl Trueman once told us in class that an error with regard to God’s sovereignty such as Open Theism would always lead back to a Trinitarian error. Now, I see why. Owen argued that the problem with the Socinian definition of person was that it assumed a limited substance. A limited substance obviously cannot have absolute authority over humanity. Therefore, a limited God such as the Socinian/Open Theistic God would be something less than a fully Trinitarian God.
Posted by Lane Keister