Between the devil's advocate and the deep blue computer

1. In chapter 4 of Where the Conflict Really Lies, Alvin Plantinga discusses quantum mechanics. Plantinga's aim is twofold: to show that quantum mechanics is compatible with miracles/special providence–as well as human/divine agents who enjoy libertarian freedom. 

Calvinists face a somewhat different challenge, and that is whether quantum mechanics is compatible with "theistic determinism". 

2. Before proceeding, we need to define our terms and draw some distinctions.

i) There's a sense in which Calvinism is deterministic. The reservation I have with that characterization is that "determinism" is an imprecise way to classify Calvinism. That's because an outcome can be determinate without being predeterminate. And there's more than one sense in which that might be the case.

For instance, if an outcome is directly caused, then it's not the end-result of a chain of events leading up to that outcome. In that regard, the outcome is determinate but not predetermined. 

To take a different kind of example, an outcome can be determinate but unintended. It wasn't predetermined in the sense of premeditation. For instance, chemical reactions are determinate but not predeterminate in that sense. 

Calvinism is deterministic is a more specific sense than generic determinism, because Calvinism has a doctrine of predeterminism in particular rather than a doctrine of determinism in general. 

Predestination is a type of premeditation. Everything happens according to God's master plan for the world. In that regard, "determinism" fails to capture the divinely intentional element of Calvinism.  

ii) Calvinism is neutral on physical determinism. Whether or not all physical events are physically determined is a matter of indifference to Calvinism inasmuch as the fundamental determinant in Calvinism is predestination. But predestination isn't synonymous with physical determinism since the locus of predestination is God's immaterial mind and will. God's blueprint for the world as well as God's resolve to implement his plan. 

iii) In Calvinism, there's more than one causal modality by which God's plan eventuates. There's God's timeless creative fiat. There's an order of second causes. And there are miracles which circumvent a chain of second causes. 

3. In addition, there are two different definitions of libertarian freedom:

There seem to be at least two different fundamental notions of what free will is in the contemporary literature. The first of these, which seems to have garnered the most attention in the last century, works under the assumption that for a person to rightly be said to have free will, she must have the ability to do otherwise than what she does, in fact, do. Under this view I could be said to have freely chosen to drive to work only if I also could have freely chosen, for example, to bike to work or to skip work altogether. This approach to free will is referred to as a ‘leeway-based approach’ (cite my book) or an ‘alternative possibilities approach’ (see Sartorio (2016).)

In contrast, a smaller percentage of the extant literature focuses primarily on the issues of ‘source,’ ‘ultimacy,’ and ‘origination’. This second approach doesn’t focus immediately on the presence or absence of alternative possibilities. On this approach, I freely choose to drive to work only if I am the source of my choice and there is nothing outside of me from which the choice is ultimately derived.

In what follows, we refer to the first of these conceptions—the conception that free will is primarily a matter of having alternative possibilities—as the ‘leeway based’ conception. Similarly, we will refer to the second of these conceptions—that free will is primarily a matter of our being the source of our choices in a particular way—as the ‘sourcehood’ conception. (John Fischer and Carolina Sartorio refers to sourcehood views as ‘actual sequence’ views; see Fischer (2006) and Sartorio (2016)).

Both of these notions can be seen in the following passage taken from Robert Kane:

We believe we have free will when we view ourselves as agents capable of influencing the world in various ways. Open alternatives, or alternative possibilities, seem to lie before us. We reason and deliberate among them and choose. We feel (1) it is ‘up to us’ what we choose and how we act; and this means we could have chosen or acted otherwise. As Aristotle noted: when acting is ‘up to us,’ so is not acting. This ‘up-to-us-ness’ also suggests (2) the ultimate control of our actions lies in us and not outside us in factors beyond our control (Kane (2005), 6). Kevin Timpe, Routledge Companion to Free Will. 

4. Apropos (3), we need to disambiguate libertarian freedom (as defined above) from Calvinism. 

i) I'd say that the ultimate sourcehood definition is straightforwardly at odds with Calvinism. Human agents can't be free in that sense.

ii) But the leeway definition is equivocal. We need to distinguish between alternate possibilities in the psychological sense in contrast to alternate possibilities in the metaphysical sense. 

By "psychological", I mean human agents can imagine alternate pathways. And when we make a choice, that often involves mentally comparing and contrasting alternate pathways.

That's consistent with Calvinism. According to Calvinism, God has predestined rational agents to make choices by engaging in that type of deliberation.

Likewise, it's consistent with Calvinism that human agents can and do influence the world in various ways. 

iii) That, however, doesn't entail that there are open alternatives in the metaphysical sense because not everything that's conceivable is feasible. Although we can entertain many apparent possibilities, it doesn't follow that we can act on all of them. Indeed, it's a commonplace of human experience that there's often a disappointing shortfall between imaginary pathways to our goal and realistic pathways to our goal. 

Pathways that seem to lie wide open may in fact have washed out bridges along the way. That's in part because human imagination is very shortsighted. When we contemplate a course of action, there are many intervening steps that fall outside our ken. 

In addition, our pathway may be blocked by other agents. What seems to be an unobstructed pathway in the mind often hits a wall when we attempt to act on our choice. 

iv) Finally, Calvinism affirms that unlike human agents, God does have leeway freedom. God can access alternate possibilities. God does have open alternatives at his disposal. 

5. One of the complications with assessing the relationship between freedom and determinism vis-a-vis quantum mechanics is the absence of an agreed-upon interpretation of quantum mechanics. There are deterministic as well as indeterministic interpretations of quantum mechanics. There's insufficient evidence to ascertain which is correct. At least according to the current state of the evidence, some deterministic and indeterministic interpretations are empirically equivalent. And it may be that even in principle, there can never be sufficient evidence to settle that dispute. It's striking the degree to which debates over the proper interpretation of quantum mechanics resorts to thought-experiments.

6. Suppose, for the sake of argument, that quantum mechanics is actually deterministic. That would amount to physical determinism at a subatomic level. If true, then that doesn't generate even a prima facie tension between predestination and quantum mechanics.

7. But suppose, for the sake of argument, that quantum mechanics is actually indeterministic. If some physical events or outcomes are physically uncaused or indeterminate, is that consistent with universal predestination?

Let's consider an analogy. At present, I believe there are computer chess players that can beat the very best human players. 

Suppose,for discussion purposes, we grant that human chess players have libertarian freedom. Suppose choosing which move to make originates with the player. 

Likewise, there's a sense in which a player has leeway freedom. As he scans the board, the pieces, and their position, many alternate pathways lie open to him. That's not just imaginary. It correspond to objective reality in terms of empty spaces on the board and different ways in which different kinds of pieces can move. There are multiple opportunities for action. In that respect, there's more than one way ahead. 

Ah, but here's the catch. Because the computer is unbeatable, every pathway leads to defeat. Every alternate course of action leads to checkmate.

It follows that a determinate outcome is consistent with indeterminate choices. Although it might seem that determinism and indeterminism are antithetical, they can be combined. Even if every pathway is indeterministic, the denouement is the same in each case. 

8. I'm not suggesting, from a Calvinistic perspective, that chess players have libertarian freedom. Rather, I'm using an a fortiori argument (a maiore ad minus). If even in the greater case, where indeterminate choices are nevertheless consistent with determinate outcomes, then mutatis mutandis, that holds true in the lesser case where leeway freedom (and ultimate sourcehood) is false. And that's an analogy for quantum mechanics, even on indeterministic interpretations, where causal determinism is false at the subatomic level.