Plantinga on Nomological Necessity
Andrew Moon of The Prosblogion has taken an interesting look at Alvin Plantinga’s argument from nomological necessity from his most recent work, Where the Conflict Really Lies . Moon raised some interesting questions of the argument (for a concise summation of the argument itself please click on the link to Moon’s article). A question he did not raise, and which I find particularly interesting, relates to the following assertion of Plantinga’s:
The sense in which the laws of nature are necessary, therefore, is that they are propositions God has established or decreed, and no creature–no finite power, we might say–has the power to act against these propositions, that is, to bring it about that they are false. (pp 281)
What interests me is not so much the content of Plantinga’s argument, which seeks to address the problematic he identifies in the necessity of natural laws by making those laws contingent upon divine authorship, but rather with the implications for this assertion of Molinism, of which Plantinga is a proponent. Specifically I would examine the proposition in light of one of the key metaphysical implications of Molinism: that the voluntary creative self-restrictions involved in the act of creation (specifically the self-restrictions involved in maintaining libertarian creaturely free will) may place necessary but incidental physical restrictions upon creation. To put it more explicitly, Molinism’s philosophical assertion of libertarian free will implies a creation whose physical laws could not be contrary to that free will.
Readers familiar with Molinism will likely be familiar with this implication, which might be termed the ‘limited creative alternatives thesis,’ though it is usually discussed in terms of counter-factuals of freedom rather than physical laws. When it comes to physical laws, however, it allows for the possibility that, just as God may have chosen between different sets of counter-factuals of freedom in the act of creation, he may have chosen between different sets of possible physical laws. He may even have chosen against his preferences in order to maintain some more valued aspect of creation (eg. he may have preferred a different set of physical laws but chose the one he did because his preferred laws did not allow for libertarian free will, a more valued consideration than physics). The question comes up when Plantinga makes the following assertion:
…theism enables us to understand the necessity or inevitableness or inviolability of natural law: this necessity is to be explained and understood in terms of the difference between divine power and the power of finite creature. (pp 283)
Specifically, in assuming the idea that physical laws are necessary in so much as they divinely-authored and beyond the capacities of creatures to be made false but contingent in respect of that divine authorship, to what degree is the necessity of physical laws a matter of divine vs. creaturely power and to what degree is it a matter of divine choice? Choice being something of a lower-order potency than power, as we can only choose amongst those alternatives that lie within our powers, are physical laws determined by divine choice (from amongst various alternatives) logically more contingent that than those established merely by an act of divine power (without choosing from amongst alternatives, merely decreeing)?
Obviously this question does not speak to the substance of Plantinga’s point but I think it is an interesting one nonetheless. Thoughts?
Notes and Bibliography
 Alvin Plantinga, Where the Conflict Really Lies: Science, Religion, and Naturalism, Oxford University Press, 2011.
 While some might argue against the choice-power dichotomy I have established I would propose that Molinism makes it necessary, as the category of middle knowledge logically implies that God chose from amongst multiple or infinite sets of true counter-factuals, all of which it was within his power to reify through an act of creation.