Calvin and Divine Simplicity
Moreover, those phantoms which Servetus substitutes for the hypostases he so transforms as to make new changes in God. But the most execrable heresy of all is his confounding both the Son and the Spirit promiscuously with all the creatures. For he distinctly asserts, that there are parts and partitions in the essence of God, and that every such portion is God.
Please excuse me for lacking page numbers or chapter divisions, the Kindle version of the Institutes I am using has none.
This passage comes in Calvin’s first chapter on the Trinity. Calvin is discussing the errors of the rationalist Servetus in this passage. Calvin points out three heresies that Servetus is guilty of: 1) He substitutes the hypostatic understanding of the Son and Spirit, and calls them merely ideas. Neither the Son or the Spirit are not divine like the Father for Servetus. 2) Servetus says that the divine nature can be divided. In other words he thinks there are metaphysical parts in God. 3) Finally, Servetus thinks that all of creation partakes of divinity.
Now (1) and (3) are not problematic for evangelicals. We all believe that the Son and Spirit are hypostases of the Trinity, and that all three persons of the Godhead are coeternal and coequal, save the distinctions in the economy of Salvation.
It is (2) I would like to camp out on. Calvin points out that anyone who is willing to divide the divine essence is a heretic. Because for Calvin, like most of the classical tradition, holds that for there to be parts in God is to diminish God’s divinity. The reason for this is because Theists typically hold that God is a se, which is the doctrine that God is not dependent on anything. But if God has parts then, he is dependent on those parts for his existence. The parts, then, would be more fundamental than God himself this flies in the face of what it means to be God in a classical sense. So, if Calvin were alive today he would condemn a great number of “orthodox” theologians.