This recently over the transom:

Dear Dr. Vallicella, I'm a reader of your blog, and have really enjoyed much of your work. Since you wrote the Stanford Encyclopedia article on the topic of divine simplicity, I thought I might reach out to you to ask your opinions on some things. I am on an e-mail list with a Christian philosopher who is extremely critical toward the idea and I'd like to know what you think of the following: First, he argues that, while there are some rationally acceptable arguments for divine simplicity, they do not rise to the level of demonstration. Based on some of your recent work, I gather you might agree with this.

BV: I do agree. The doctrine cannot be demonstrated or proven. There are 'good' (rationally acceptable) arguments for the doctrine of divine simplicity (DDS), but they are not rationally compelling. To my mind this is but a special case of a general thesis: few if any substantive theses in philosophy are demonstrable or provable.

It's the second part I'm curious about. Further to his argument is that divine simplicity rests on questionable metaphysical premises, and that many are far too confident in the position given their familiarity with metaphysics. He is exceptionally critical of James Dolezal , saying that consulting him on the topic "is like going to a bike shop to get your car repaired." He believes that, for one to really understand and engage with the ideas, academic training and great philosophical experience is required (which Dolezal may not possess, not having earned his Ph.D. under recognized philosophers). Since you cite Dolezal multiple times in your article, I assume you would disagree with this at least on some level. While I only have undergraduate philosophical training, I am familiar with the debates on the subject, and the metaphysics involved, to have at least some rational justification for my opinions. (The big exception is questions of simplicity and modal logic—I back off when things go into that territory). So, my actual questions: what level of philosophical training (especially official) is necessary to engage in these debates? And is his evaluation of Dolezal in particular correct?

BV: Dolezal is competent, and your friend's 'bike shop' comment does nothing to show otherwise. You don't really need any 'training' other than what you can provide for yourself by careful study of the literature on the topic, assuming you are above average in intelligence and have a strong desire to penetrate the problem. I don't set much store by training and trappings and academic pedigrees. What matters in philosophy is love of truth, intense devotion to her service, intellectual honesty, and the willingness to follow the arguments whither they lead.

Second, he has a criticism of simplicity I haven't seen anywhere else. I'll have to summarize it as the paper has not been published. It goes like this: a key premise in the argument for simplicity is that whatever has parts depends on those parts, and so must be composed by something else. God is not dependent/composed by anything else, therefore he must be simple. He questions this idea and puts forward an "individuals first" account, suggesting that parts are in some cases only definable by the wholes of which they are parts, thus actually making the parts dependent on the whole. He provides two possible examples: the notions of necessity and possibility, which are dependent on each other for their definitions; and the doctrine of the Trinity, where Father, Son, and Spirit are exclusively defined in terms of relations among them. This suggests, he argues, that we can conceive of wholes that have parts, the parts all being mutually dependent upon one another and thus not composed by anything else. And so, God might have parts while not being composed by anything else. What are your thoughts on this idea?

BV: One kind of whole can be called compositely complex, while another can be called incompositely complex. A wall of stacked stones is a complex of the first sort: its parts (the stones) can exist without the whole (the wall) existing, and each stone can exist apart from any other. The parts can exist without the whole, but the whole cannot exist without the parts. Such a whole needs an ontological factor, a 'composer' to ground its unity and to distinguish it from a sheer plurality. The wall is not a sheer manifold, a mere mereological sum of stones, but a unitary entity. It is one entity with many parts. God cannot be complex in this way. For then he would depend for his existence and nature on the logically/ontologically prior existence of his parts including his attributes (omniscience, omnipotence, etc.) if these are assayed as 'parts' or ontological constituents of God.

Now your friend's suggestion seems to be that God is an incompositely complex whole of parts. God has parts, but these parts cannot exist apart from the whole of which they are the parts, and no part can exist apart from any other part. The parts are then mutually dependent and inseparable.

I don't think this works. Consider the 'composition' of essence and existence in a contingent being such as Socrates. The 'parts' -- in an extended sense of the term -- are mutually inseparable. The existence of Socrates cannot itself exist apart from his essence and the essence of Socrates cannot exist apart from his existence. And neither can exist apart from Socrates, the composite of the two. But Socrates is a creature and God transcends all creatures. His absolute transcendence cannot be accommodated by any scheme that allows God to be in any sense partite, not even if the parts are mutually inseparable. God's absolute transcendence requires that he be absolutely simple. God belongs at the fourth level in the following schema:

Level I. Pure manyness or sheer plurality without any real (as opposed to mentally supplied) principle of unity. Mereological sums. The sum just is its members.

Level II. Composite complexity. A whole of parts the unity of which is contingent, as in the case of the stacked stones. There is one wall composed of many parts, but the parts can exist without the whole. The whole, however, cannot exist without the parts.

Level III. Incomposite Complexity. Wholes the parts of which are mutually inseparable, whether weakly inseparable or strongly inseparable. Suppose a particular cannot exist without having some properties or other, but needn't have the very properties it in fact has, and (first-order) properties cannot exist without being had by some particulars or other, but not necessarily the particulars that in fact have them. We then say that particulars and properties are WEAKLY mutually inseparable. If, however, particulars cannot exist without having the very properties they have, and these properties cannot exist without being instantiated by the very particulars that instantiate them, then particulars and properties are STRONGLY mutually inseparable.

Level IV. Absolute Simplicity. The absolutely simple transcends the distinction between whole and parts. Whereas in Socrates there is a real distinction between essence and existence despite their strong mutual inseparability, in God there is not even this distinction.