This is a magnificently fine book. Richards seeks to offer a robust defense of classical theism, yet he is sensitive to the challenges. He mostly succeeds.
Thesis: “Christians should affirm that God has an essence, which includes his perfections and essential properties, and should attribute to God essential and contingent properties” (Richards 17).
Essentialism: belief that so-called ‘de re’ modality is relevant to our understanding of God. It is appropriate to speak of a cluster of properties which God necessarily exemplifies and without which he would not be God, and contingent properties which he only has in some possible worlds (18 n1).
In chapter 2 he gives a dizzying, yet helpful account of modal logic. He presents the S5 system, in which all possible propositions are necessarily possible. This allows him to draw upon Plantinga’s account of possible worlds as “maximally consistent states of affairs.”
The definition of essence is a set of properties that an entity exemplifies (64). A property is some fact or truth about an entity in the world. In our usage we want to say that Socrates has necessary/essential properties without saying that Socrates is necessary to every possible world. We would say it like this:
“S has P and there is no W in which S has the complement ~P of P.
Property actualism states that S has no properties in worlds in which he does not exist.
□(x)(P(x) → E(x))
Therefore, The essentialist argues that there is a distinction between essential divine properties and accidental (contingent) divine properties (90). Property: a state of affairs concerning entities of different types. While saying there are contingent properties in God seems to depart from the tradition, it really doesn’t. God’s deciding to create the world is a contingent divine property. God has P in every world. God’s essence is concretely instantiated in every possible world (95). God’s essential attributes, those he has in every possible world, are divine ‘perfections’ (96). “They include all those properties susceptible to perfection.”
Richards has several chapters on Barth and Hartshorne, noting some promising moves in the former and rebutting the latter. The chapter on Barth traded on an unresolved question: Did Barth hold to strong actualism? I think he did. Richards isn’t so sure.
He ends the book with a fine chapter on divine simplicity, noting the numerous ways it has been employed in the Tradition:
(1) all divine properties are possessed by the same self-identical God.
(2) God is not composite, in the sense that he is not made up of elements or forms more fundamental than he is.
(3) God’s essence is identical with his act of existing.
(4) All God’s essential properties are coextensive.
(5) All God’s perfections are identical.
(6) All God’s properties are coextensive
(7) God’s essential properties and essence are strictly identical with himself.
(8) All God’s properties are strictly identical with himself.
Question: when the medieval denied God has accidents, is he denying what the essentialist is affirming, that God has contingent properties (225)? Maybe not. The essentialist, for example, says contingent relations are divine accidents, but Thomas calls these external relations ad extra.
The medievals denied that “goodness” and the like were accidental to God, because they (rightly) wanted to deny that God participates in the form of Goodness. But this isn’t what the essentialist is claiming.
Therefore, the essentialist accepts (1)-(4), noting that “existence” today doesn’t have quite the same connotations as existence did for Thomas. (5) is tricky. (6) seems unproblematic. (7)-(8) are deeply problematic.