Can you explain something by appealing to a “brute fact”?

Prof. Keith Parsons and I have been having a very cordial and fruitful exchange.  He has now posted a response to my most recent post, on the topic of “brute facts” and explanation.  You can read his response here, and find links to the other posts in our exchange here.  Since by the rules of our exchange Keith has the last word, I’ll let things stand as they are for now and let the reader imagine how I might respond.

Another one of my old sparring partners, Prof. Robert Oerter, raises an interesting objection of his own in the combox of my recent post, on which I will comment.  I had argued that if we think of laws of nature as regularities, then no appeal to such laws can explain anything if the most fundamental such laws are regarded as inexplicable “brute facts.”  Oerter writes:

To change the example, consider: “The cause of the forest fire was the lightning that hit that tree.”

Suppose the lightning was a brute fact (a bolt out of a clear blue sky, as it were). How does its brute-fact-ness in any way decrease its explanatory power? It's still the cause of the forest fire, isn't it?

End quote.  Now, let me first reiterate that my remarks in the earlier post were about, specifically, laws of nature understood as regularities.  Even if Oerter’s example were a case of a brute fact serving as a genuine explanation, that wouldn’t affect the point that laws understood as regularities wouldn’t be true explanations if the fundamental level of laws were a brute fact.  (And Oerter may well agree with that much, for all I know.) 

But Oerter’s question is still a fair one.  Whatever we think of the regularity view of laws, we might yet wonder whether other kinds of thing might be genuinely explanatory even if they were brute facts.  Wouldn’t Oerter’s imagined bolt of lightning be a good example? 

I would say that on analysis it would not be.  Consider first that we can distinguish a metaphysical sense in which something might be claimed to be a “brute fact” from an epistemological sense in which it might be.  Something would be a brute fact in the epistemological sense if, after exhaustive investigation, we did not and perhaps even could not come up with a remotely plausible explanation for it.  Something would be a brute fact in the metaphysical sense if it did not, as a matter of objective fact, have any explanation or intelligibility in the first place.  With a metaphysical brute fact, it’s not merely that we can’t discover any explanation, it’s that there isn‘t one there to be discovered.

Now I do not deny that there could be epistemological “brute facts,” but only that there could be metaphysical brute facts.  But it seems clear that whatever plausibility Oerter’s example has derives entirely from the possibility that a bolt of lightning of the sort he imagines might be an epistemological brute fact.  For we can certainly imagine cases where a bolt of lightning strikes and causes a forest fire but where there was only clear blue sky and no storm clouds present, nor even some bizarre cause (a gigantic Tesla coil, say, or an angry Thor flying about).  But that by itself is just to imagine unexplained lightning appearing.  It does not amount to imagining lightning that as a matter of objective fact has no explanation suddenly appearing.  (And as I have argued in several places, and at greatest length in Scholastic Metaphysics, in fact we cannot, contra Hume, coherently describe a case where this latter sort of thing happens.)

Indeed, it isn’t even quite right to say that what Oerter is describing is a case of a cause that is entirely epistemologically “brute,” let alone metaphysically brute.  For of course, the reason why we’re willing to regard an unexplained instance of lightning as a cause of a forest fire is that we know a lot about lightning in general, such as that it can cause forest fires.  So, whether or not we know the source of the lightning Oerter asks us to imagine, we know at least that it is lightning, and it is because we know that it is an instance of that general class of thing that we regard it as the sort of thing that could cause a forest fire.  We know, in effect, its formal and material causes insofar as we know that it is lightning rather than (say) a hallucination or some atmospheric condition that merely superficially resembles lightning.  And we know also its final cause insofar as we know that it has certain causal powers such as the power to ignite wood, where casual powers are “directed” toward their outcomes as toward an end.  What we lack is, at most, merely knowledge of the lightning’s own efficient cause.  Precisely for that reason, though, the lightning is not a “brute fact,” full stop, either metaphysically or epistemologically, even if there is an at least epistemologically “brute” aspect to it. 

But we can say more.  For the lightning causes the forest fire precisely insofar as (the Aristotelian will say) it actualizes the potentiality of whatever foliage it strikes to catch fire.  But the lightning can do this only insofar as it is itself actualized (for, since the lightning is not a necessarily existing thing, it too has to go from potential to actual).  And whatever is actualized (so the Aristotelian will also say) is actualized by something already actual.  Now what we’ve got in any case where C is actualized by B only insofar as B is in turn actualized by A is an essentially ordered causal series, in which the action of the members lower down in the series is unintelligible apart from the impartation to them of causal power by members higher up in the series.  This, of course, is the basis for Scholastic arguments to the effect that the lightning could not exist and operate at all even for an instant apart from a purely actual (and thus divine) conserving and concurring cause, who is first in the essentially ordered series in question.  But that conclusion can be bracketed off for present purposes.  What matters for the moment is just that on the Scholastic analysis, the lightning cannot intelligibly actualize without itself being actualized (whether or not this regress leads us to a divine first actualizer).

So, to conceive of the lightning as a cause of the fire, we ultimately cannot avoid thinking of it as having an efficient cause of its own -- at least to conserve in being, and concur in, its causal activity at the moment at which it actualizes the fire.  Hence our grasp of its being a cause of the fire entails bringing in all of the four causes, in which case it is hardly an unintelligible “brute fact.”  Of course, this analysis brings in specifically Aristotelian-Scholastic metaphysical notions, but there is nothing suspect about that.  For in order to evaluate a claim like Oerter’s claim that a bolt of lightning can be a genuine explanation even if it had no explanation of its own, we need to ask ourselves what it is to be an explanation in the first place, and in particular what it is to be a causal explanation (since the lightning is in the case at hand claimed to provide a causal explanation of the fire).  And the Scholastic holds, on independent grounds, that formal, material, final, and efficient causes are all part of a complete explanatory story. 

If Oerter or anyone else wants to reject this metaphysical picture they are free to do so, but then they have to provide an alternative metaphysical story about how explanation and causation work -- and it has to be a story on which the lightning could be a genuine explanation of the fire without having an explanation of its own.  Merely suggesting that the fire would be an explanation even if it lacked an explanation of its own is not enough, for this either fails to describe the situation in sufficient metaphysical detail to allow us to conclude anything from it (if no account of explanation and causation is given) or it will beg the question (if some non-Scholastic account of explanation and causation is implicitly being presupposed). 

I would say that what would clearly make Oerter’s case is an example where it is evident both (i) that A genuinely explains B, and yet (ii) that A has no formal, material, efficient, or final cause of its own.  In such a case A itself would clearly be a “brute fact.”  But I submit that no such example is forthcoming.  For the more we peel away formal, material, final, and efficient causality from our conception of A, the more we, by that very fact, peel away anything in A that could make of it an explanation of B or of anything else.   A cause is intelligible as a cause only insofar as it is intelligible in itself. 

[For earlier posts on related matters, go here and here.]