Having set forth a defense of the traditional teaching in the previous installments (1, 2, 3), let me now examine the reasons it has been rejected, admitting that reducing their criticisms to a single sentence cannot but be reductive. I noted these critiques in the third installment:

1. It cannot resolve the theoretical problem of evil: if God is eternal and simple, then what God knows God wills; evil will be directly willed by God (process theology).
2. It cannot resolve the human freedom and divine foreknowledge dilemma: if God is simple and eternal, then human agents who are caused by God are determined by what God knows and consequently, they are not free (open theism).
3. It is logically incoherent. If God is simple and eternal, then somehow God cannot have real relations “internal” to God or “external” with creation (analytic theologians).
4. It offers us a deity made in the image of a Eurocentric theocrat who cannot be moved by the oppression and sorrow in the world (liberation theology).
5. It subordinates a dynamic, biblical sense of history to a Hellenistic substance metaphysics and cannot make sense of God’s becoming in the incarnation or divine processions (anti-metaphysical Barthians).

Are these sufficient reasons to reject a teaching shared diachronically and synchronically among every Christian church, and nearly every theologian prior to the seventeenth century?

My brief response is no. The three previous installments offer a lengthier argument, but in this final installment I want to make a negative argument, a positive argument, and an argument about the nature of theology. First, the negative argument. Many of the criticisms above are circular. They assume what should be demonstrated. They assume that God and creation can be placed on a single continuum and thus the two compete for “space” and “time.” If God has no “real” relation with creation, then God is not relational. If God is omnipotent and free, then creatures cannot be. For this reason, they are inattentive to a reasonable argument that three sets of relations should require different theo-logics, relations noted in the second installment:

1. God’s real triune relations
2. God’s logical relation to creation
3. Creation’s real relation to God

Simplicity helps us attend to the different logic that must differentiate these relations for if we confuse (1) and (2), as almost all of the above critiques do, then we have no way of affirming that God is not less but much more relational than human creatures can be. Divine simplicity affirms that God is more intimate to me and others than we can be to ourselves or each other.

The positive argument is that no theologian has, or should, simply affirm “simplicity” qua simplicity. Here is where I think some common cause could be made among those who critique it and those of us who affirm it. It is simplicity mediated through Trinity that should be affirmed. Some forms of simplicity have been, and should be, rejected. Proclus stated, “Whatever is simple in its being may be either superior to composite things or inferior to them” (The Elements of Theology, proposition 59). No Christian theologian would argue that a simplicity that is inferior to composite beings should be attributed to God. We should attend to the positive reasons the Cappadocians, Augustine, Aquinas, Luther, Arminius, and Wesley affirmed it. At their best, they understood that it helps us confess God is one, as we must do as persons committed to the revelation to Moses, and as three persons without violating that unity, which we must do as Christians. Simplicity allows us to say what strains our language, which is always a creaturely reality. The God who has no potentiality can yet be in God’s triune relations, gift and reciprocity. The God who is immutable, can also “proceed” from Father to Son, and to Spirit, without turning God into a changeable creature. Only when simplicity helps us first speak of God in divinis so that we can also speak of God as three persons without losing unity, should simplicity be affirmed.

A final reason to affirm simplicity has to do with the nature of theology. What do we as theologians do? We are seeking to set forth in language an “object” that cannot be like any other object in the world. God cannot be indicated, as though we can point to something and say, “That is God.” The relation between divine simplicity, perfection, and Trinity maintains the difference God is. It also requires an element of paradox and mystery that many theologians may find difficult to affirm. God is, as Balthasar noted, a mystery to be inhabited and not a logical puzzle to be solved. To be frank, atheism solves some of the theoretical problems identified above better than a reconceived deity who in the end requires such a rupture in the Christian tradition that it also requires us to confess that no one prior to the eighteenth century, or perhaps prior to Hegel, knew what they were doing. No one “masters” divinity. The perfectly, simple Triune God asks us to be reticent in using God to solve logical problems rather than receive God in the sacred wisdom that has come down to us.