#818 Are Quantum Fields the Metaphysically Necessary Ground of Being?

Dr. craig’s response

You’re quite right in saying that in my previous publications I have considered so-called fundamental particles like quarks and electrons to be truly fundamental and so possible candidates for the office of metaphysically necessary being that is sought by Leibniz’s argument from contingency. I argued that these particles seem to exist contingently and so are not plausible candidates for the metaphysically necessary sufficient reason of the world.

But these particles can be viewed as excitations of an even more fundamental reality, namely, quantum mechanical fields. So in my forthcoming systematic philosophical theology, I consider whether the atheist might not plausibly claim that these quantum fields are the necessary ground of being rather than God.

Here I’m inclined to agree with your quotation from Stephen Barr that such quantum fields are also contingent. Barr’s final point seems to be that such fields are not nothing, as people like Lawrence Krauss have claimed, and so fail to explain the universe’s origin from nothing at some time in the past. But for the purposes of our discussion, Barr’s quotation also makes a different and important point, namely, that these quantum states are contingent. I think, however, that it’s highly misleading to refer to such states as “no-universe quantum states.” Rather these states just are the universe at its most fundamental level of description.

As Barr intimates, there are numerous such states, such as six fields for the quarks, three for the electron and its siblings, three for the neutrinos, and so on; in all seventeen different fields according to the standard model of particle physics. Cosmologist Luke Barnes summarizes the situation:

I think you can see that such fields do not exhibit the desired unity, simplicity, and necessity that you mention. The idea that these different fields, their interactions, and their constants could all be metaphysically necessary seems no more plausible than the claim that the universe is metaphysically necessary. 

Most decisively, even if all of the features listed above were metaphysically necessary, we still might wonder why this theory holds. For example, string theory is an alternative to quantum field theory. Yet no one would think that string theory is metaphysically impossible; it needs to be assessed scientifically. Even if you say that the laws of nature are metaphysically necessary, that this is the only way that quantum fields could have behaved, nevertheless the laws of nature could still have been different because there could have been different substances than those that exist, endowed with different dispositions and different properties, so that you would have a whole different set of laws of nature. I think it would be utterly implausible to say that such a universe would be our same universe. That would be like saying that a pane of glass could retain its identity if it had been made of steel instead. That seems obviously absurd. It would not be the same window if it were made of steel instead of made of glass. So I think we have quite good grounds for thinking that in virtue of its composition the universe doesn’t exist metaphysically necessarily. That is probably why very few, if any, contemporary atheists take this route to try to escape from the contingency argument.

I have the sneaking suspicion that when it comes to the emergence of the universe from its underlying quantum states, you’re thinking of this happening chronologically. But that’s not right. Don’t think of the universe’s emergent properties as arranged “horizontally” in a temporal sequence of states at the same level; rather think of them arranged “vertically” as a hierarchy of levels of states. Just as water has certain emergent properties like wetness that its atomic constituents, hydrogen and oxygen, do not have, so the universe has certain emergent properties that its underlying quantum states do not have. The fact that these quantum fields are not intended to be chronologically prior to the universe is evident from the fact that the argument from contingency contemplates an eternally existing universe, one that never began to exist. The atheist response that we are considering says that even though the emergent universe we observe is contingent, nonetheless its underlying quantum states are metaphysically necessary.

Of course, if the universe did begin to exist, then we have a second reason for thinking that the universe does not exist by a necessity of its own nature, namely, the fact that it came into being. If something exists necessarily, then it must exist eternally because if it begins to exist that shows that its non-existence is possible. It came into being. So an essential property of a necessarily existing being will be its eternality – being without beginning or end. We have now pretty strong evidence that the universe is not past eternal but had a beginning, which would show its contingency.

This takes us into the kalām cosmological argument, which is based upon the beginning of the universe. I want to keep the theistic arguments as independent of one another as we can because then the probabilities of these independent arguments in favor of God's existence accumulate. Nevertheless this does show how the arguments dovetail with one another and reinforce one another. If the universe does have a beginning, that reveals the contingency of the universe. Not only that, but it reveals that the universe is contingent in a very special way, namely, it came into being out of nothing. For the universe to exist contingently and to have a beginning seems to be doubly absurd because it comes into existence without any explanation whatsoever out of nothing. The kalām cosmological argument powerfully reinforces the argument from contingency by underlining the contingency of the universe in a very special way. If the universe had a beginning, then that makes its contingency all the more obvious.