The second edition of Richard Swinburne’s Existence of God was published in 2004. I imagine most analytic philosophers of religion consider it to be the most important work on natural theology written in the past hundred years or so. To say that the volume has been influential would be an understatement. Applying Bayes theorem to natural theology, Swinburne created a paradigm for how philosophers of religion would argue for or against the existence of God. While not all philosophers of religion are sympathetic to Swinburne’s methodology, one can’t reasonably deny Swinburne’s fingerprint in the field today. And yet, Swinburne’s revised edition is now twenty years old.
A lot has happened in analytic philosophy in the past twenty years. Clearly indebted to Swinburne, Joshua Sijuwade looks to develop his own methodology for natural theology while taking into account recent developments in contemporary metaphysics. Sijuwade’s volume is broken up into two parts. The first part relates to developing and motivating his methodology, while the second part of the volume looks to apply and contrast his metaphysical framework with its competitors, at least, as it relates to explaining contemporary physics and metaphysics.
Part 1: Explanatory framework
Chapter 1 is a primer on contemporary metaphysics and philosophy of religion. Sijuwade discusses everything from evidentialism about religious belief to recent developments in mereology and free will. By surveying recent developments in metaphysics, the chapter lays a foundation which Sijuwade can pull from when he later discusses how his metaphysical framework best makes sense of the paradigms in the field.
Chapter 2 then discusses the nature of explanation and argues that we embrace a version of Inference to the Best Explanation, which he calls The Inference to the Loveliest Explanation. Here we should prefer a theory over its counterpart if the theory possesses coherent virtues (e.g., internal and universal coherence), aesthetic virtues (e.g., simplicity), and evidential virtues (i.e., virtues related to a theory’s explanatory power) (p. 67). Sijuwade prefers this approach to a standard Bayes analysis as discussing a theory’s intrinsic probability as it relates to God is too controversial (p. 27).
Chapter 3 then dives deep into the question of fundamentality. Should we think that there is an ultimate grounding that lacks further explanation (i.e., metaphysical foundationalism)? Or perhaps we should think there are no truly fundamental entities, and every entity can be explained by an infinitely descending chain of entities (i.e., metaphysical infinitism) (p. 87). Among other reasons, for simplicity and unification concerns, Sijuwade endorses metaphysical foundationalism over metaphysical infinitism (p. 106).
Chapter 4 ends the first section by articulating what he takes to be the best candidates for the most plausible foundationalist theory. Sijuwade offers what he calls a Trope-Theoretic Theism as the best hypothesis. Roughly, Sijuwade argues that God is a powerful trope. And as a powerful trope, God is a fundamental abstract particular, a particular that is self-exemplifying (pp. 118–120). In a Swinburnian fashion, Sijuwade argues from the trope’s maximal power, that the trope would have maximal knowledge and maximal goodness (p. 130).
Of course, in order to develop a best explanation, one must compare one’s preferred theory to alternatives. Sijuwade bifurcates the main alternatives into monistic theories of foundationalism and pluralistic theories of foundationalism. An example of the former would be monistic substantivalism. On this view, the Cosmos is what is fundamental. It is a space-time substance where material objects amount to space-time regions of the Cosmos. Objects are parts of the substance (p. 156). Sijuwade questions whether there really is internal consistency here. ‘On the one hand, MS suggests material objects have specific properties and identities grounded in their respect to space-time regions. On the other hand, it posits the Cosmos as fundamentally indivisible, challenging the basis for treating these regions – and thus material objects – as distinct entities’ (p. 163). Sijuwade also raises concerns to substantivalism that relate to its simplicity (p. 164). While monistic substantivalism postulates only one fundamental substance (space-time entity), there are various fundamental properties that also exist. The one fundamental substance is said to instantiate countless universals or tropes. On Sijuwade’s Trope Theism, we only need to postulate one fundament property (p. 164). Sijuwade makes similar arguments with respect to other competing theories, such as Pure Stuff theory, Mereological Bundle Theory, Extended Simples Theory, and Priority Based Structuralism. As the reader might imagine, Trope-Theoretic Theism comes out on top.
Part 2: Explanatory analysis
The next stage of the book moves to discuss which metaphysical theory of fundamentality has better explanatory or predictive ability when it comes to explaining quantum physics, eternal block theory, the existence of diverse essences, free will, and the like. Sijuwade again resorts to Swinburne-style reasoning to argue that we should expect the aforementioned data on the hypothesis that God is powerful and good. He’d likely share His goodness and create a universe (p. 151), specifically, one that displays not just temporally existing goods, but goods that would permeate eternally (p. 304). He’d also likely create diverse essences that become knowable within that universe which also reflect His essence (pp. 356–358). But Trope Theoretical Theism’s competitors fail to make sense of the data. For example, when it comes to account for the existence of diverse essences, since monistic substantivalism says all objects are reduced to space-time regions of one fundamental substance, can we even say that individual and diverse essences exist (p. 362)? Similarly, how can Monistic Substantivalism make sense of a rich four-dimensional reality? As Sijuwade puts it, ‘If every temporal moment has its own distinct set of circumstances and entities that exist within it, then there must be a mechanism within any comprehensive metaphysical theory to account for these variations. But the singular, static substance of MS offers no such mechanism’ (p. 307). Sijuwade ends his volume by developing his own soul-making theodicy to argue that his Trope-Theoretic Theism makes sense of evil (p. 538). All things being equal, we should believe that God exists.
Concluding thoughts
The range of metaphysical issues addressed, the technical level of the volume, and the amount of cutting-edge metaphysicians who are engaged, all make for an impressive volume. Those who are serious about contributing to the project of natural theology should become familiar with this work. Saying this, I imagine not everyone will be interested in reading over 600 pages of technical philosophy. Nonetheless, the book can act as a reference for those seeking a primer on contemporary metaphysics and for those seeking how big-picture objections to alternatives to theism can be developed.
I’ll now express my biggest concern for the project. Sijuwade thinks of God as an entity, specifically a trope. Sijuwade suggests that we can make confident assertions about what God would likely do given his attributes, or to be more precise, the sort of trope God is. Is it right to think of God as an abstract particular? Without appealing to circularity, how can God be the grounding of all tropes or of all things, if He is a trope or a thing? Sijuwade is confident about what God would or wouldn’t likely do based on God’s attributes. I worry that this assumes something more akin to univocal predication than the analogical predication plausibly endorsed by the Lateran IV. If God is another object in the realm of existent things, I can see why we should treat God as a hypothesis and why it makes sense to try to prove the hypothesis through a scientific method. We know the realm of existent things through this method, God wouldn’t be an exception. But if God is no-thing, as He is beyond existence, perhaps the methodology is misguided. Maybe there is a better methodology available to us. Perhaps a methodology that would not just make it likely that God exists but that gives us metaphysical certainty and can act as a demonstration or proof, and thus, vindicate Vatican I. Of course, my Protestant readers might not care about Vatican I or the Lateran IV but, as a Catholic philosopher, I know Sijuwade will. I’d like to have seen some engagement with these concerns in Sijuwade’s work. Perhaps Sijuwade will tackle these obstacles in future work!