So I’m a bit late to the party, but I was recently able to listen to the debate between Sean Carroll and Luke Barnes on the Unbelievable podcast. There’s been some hubbub on Randal’s blog about the rather fantastic episode, and I’d like to make a few points now that I’ve heard it myself.
A lot of the debate was on the ground regarding a naturalist explanation of the universe, assuming the universe (defined as the entirety of physical reality) has a beginning. The two of them didn’t debate any merits of naturalistic explanations of an eternal universe.
The first bit of hubbub I’m referring to is when Randal accuses Sean of redefining god to not be necessary and to argue against his own definition of god as a non-necessary being.
I think part of this stems from confusion on Randal’s part of what Sean was saying. In his book, Sean argues that there are no necessarily existing beings, so this isn't an imposition of a new definition it's an argued conclusion. Further, in the debate with Luke, Sean’s main point is that even on theism one has to accept brute facts. It's this second point of contention that I really want to focus on here.
I think that last point has more purchase than the former. Even if we grant the theist that they believe god exists necessarily, ie. he exists in all possible worlds with the same properties, the theist is still stuck having to accept a number of brute facts.
Consider the Christian idea that their god is a trinity: father, son, and holy spirit – three persons in one god.
Coherence objections aside, why is it a fact that god is a trinity rather than a single person, or duet, or quintuple, ad infinitum?
This is a fact that has no explanation, and so it is a brute fact.
I notice that on Randal’s page he refers to a brute fact as a “contingent fact that has no explanation” but that’s not the usual definition of a brute fact: which is just a fact that has no further explanation. It seems odd to me to want to import ideas about possible worlds (necessary vs. contingent), since we’d need a robust theory of talking about possible worlds to really hash out what is meant here – and there is a wide variety of views available on the topic.
If you’re familiar with my Countering the Moral Argument series, you’ll know that a theist has to accept brute facts about the properties of gods nature. This is because if a theist holds to the idea that god’s nature serves as the ontological basis for moral values – so that something like love is good only because god’s nature is loving, then the fact that god’s nature is say truthful instead of deceitful is itself a brute fact. This is because to say that god’s nature is the ontological foundation for goodness itself expressly leaves no reason as to why god’s nature has any given property. This is the main thrust of Erik Wielenberg’s arguments regarding theistic morality.
I posted this on Randal’s blog as a comment, where Randal replied:
“God's triunity and moral perfection, for example, are understood to be necessary facts about God across all possible worlds, not merely contingent brute facts in the actual world.”
But this misses the mark. First Randal is importing the idea that for something to be a brute fact it has to be a contingent fact. Even if we grant that theists hold that god is a necessary being, that is he exists the same way in all possible worlds, there is still no explanation as to why god has the properties he does. For instance, let’s say Christianity is false but Islam is true, so the idea of god as a trinity is false – god exists, but is constituted of only one person not three and he exists this way in all possible worlds.
There’s nothing logically necessary about god having to have this property. There is no logical deduction to be had from “god exists” to “god has the property of being triune”.
I just don’t see how doing a top down imposition of “well I conceive of god having XYZ properties and being necessary, so the fact that god has XYZ properties is explained by his being a necessary being” actually adds anything to explaining why god has those properties.
Consider if an atheist said that “whatever the fundamental nature of physical reality is, it’s necessary”. So when a theist uses the fine tuning argument to say that a physical constant having such and such a value is evidence for god, because if it were ever so slightly different then life couldn’t have existed in our universe, the atheist could just respond “but since I conceive that physical reality is necessary, the fact that we observe such and such a value for any given constant is explained by the necessary nature of physical reality”.
It’s really exactly like that when it comes to something like the trinity, where persons in the godhead = 3 instead of any other number.
If that move is valid, I certainly don’t begin to see how having a “necessary fact” as your starting point give any advantage over a brute fact.
In the end however, I don’t see how any worldview avoids having some set of brute facts baked into its assumptions.