Molinists have the ability to give a distinctive pre-established harmony account of how the exceptionless truth of deterministic laws of nature could be made compatible with libertarianism.
Here is the story. God considers possible worlds where dualistic agents have the causal power to miraculously contradict the physical laws in their free choices, but where outside of exercises of free will, there are elegant deterministic mathematical laws governing the world. Call such worlds Candidate Worlds.
God then narrows his consideration to Finalist Worlds, which are Candidate Worlds that are feasible—i.e., compatible with the Molinist conditionals—and where as it happens the agents’ free choices accord with the elegant deterministic mathematical laws that govern the rest of the world.
And then God wisely and prudently chooses one of the Finalist Worlds for actualization.
On this story, there are elegant deterministic mathematical laws of nature which are true even of the agents’ choices, but they are true of the agents’ choices because the agents freely chose as they did. The agents had the causal power to violate, say, the conservation of momentum, but in fact freely did not do so.
There is an ambiguity in the concept of “exceptionless laws”. “Exceptionless laws” could mean: laws that allow no exception (they are pushy laws that are so strong as to make no exception possible) and laws that in fact have no exception. The deterministic laws in this story are exceptionless in the sense of having no exception, which is why I am talking of their exceptionless truth rather than their exceptionless power.
In this story, there is a dual explanation of the agents’ choices. On the one hand, there is a standard libertarian story about the agents’ free causality. On the other hand, the laws have explanatory power, because God chose the Finalist Worlds because they are worlds where the laws have exceptionless truth.
The big difficulty with the above story is Molinism. Also, it is worth noting that it is metaphysically possible that there turn out not to be any (feasible) Finalist Worlds: in that scenario, God wouldn’t be able to create a world where there is freedom and elegant deterministic mathematical laws holding exceptionlessly. But for reasons similar to why many people think Transworld Depravity is unlikely to be true, I think it is unlikely that there would be no Finalist Worlds.
It is also interesting to note that there are two more views that could be plugged into the story that can do the same job: Thomism and compatibilism.
On Thomism, God can use primary causation to make agents freely choose as he desires. Then we can suppose that God surveys the same Candidate Worlds as on the Molinist story. Then he chooses Finalist Worlds as those Candidate Worlds where the agents’ free choices in fact do not contradict the mathematical laws. And then God uses primary causation to actualize one of the Finalist Worlds. Again, the agents have the power to contradict the laws, but freely choose not to exercise it.
Finally we have straightforward compatibilism. A dualist can just as easily be a compatibilist as a materialist. On this story, we skip the Candidate Worlds, and the Finalist Worlds are worlds with compatibilist agents, with a deterministic non-physical mental life, who have the power of contradict the physical laws of the world but who are mentally determined, in a way compatible with freedom, never to exercise such a power. And then God chooses one of the Finalist Worlds. The agents then are as free as any compatibilist agents.
The compatibilist version of this story is close to Leibniz’s pre-established harmony, except that it has real mind-world causation, which is a big improvement.
Of course, the non-theist can’t make any of these moves. And, alas, neither can I, since my mere foreknowledge view denies Molinism, Thomism (about free will) and compatibilism.