An exchange with Keith Parsons, Part IV

Here I respond to Keith Parsons’ fourth post.  Jeff Lowder’s index of existing and forthcoming installments in my exchange with Prof. Parsons can be found here.

Keith, as we near the end of our first exchange, I want to thank you again for taking the time to respond to the questions I raised, and as graciously as you have.  You maintain in your most recent post that explanations legitimately can and indeed must ultimately trace to an unexplained “brute fact,” and that philosophers who think otherwise have failed to give a convincing account of what it would be for the deepest level of reality to be self-explanatory and thus other than such a “brute fact.”  Unsurprisingly, I disagree on both counts.  I would say that appeals to “brute facts” are incoherent, and that the nature of an ultimate self-explanatory principle can be made intelligible by reference to notions that are well understood and independently motivated.

 
Now, a number of philosophical issues come up in your post that are bound to arise in a discussion of this topic -- laws of nature, the principle of sufficient reason (PSR), the principle of causality (PC), Humean and other objections to PSR and PC, and so forth.   Obviously we cannot address all this in any depth in a series of blog posts, especially given the word count Jeff has asked us to abide by.  I have addressed all of these issues in detail in my new book Scholastic Metaphysics: A Contemporary Introduction.  For the moment let me summarize a few key points.

First, I would say that appeals to laws of nature are far more problematic than most naturalists seem to realize.  For what is a law of nature, and why does it operate?  Like some contemporary philosophers of science and metaphysicians who have no theological or Scholastic axe to grind (e.g. Nancy Cartwright, Brian Ellis, Stephen Mumford) I would say that what we are describing when we talk of “laws of nature” are really just the ways a thing will tend to operate given its nature or essence.  In that case, though, the existence of a law of nature presupposes, and thus cannot explain, the existence of the concrete physical things, with their distinctive natures, whose operations the law describes -- in which case laws of nature are not available to the naturalist as a terminus of explanation (“brute fact” or otherwise).

Suppose this neo-Aristotelian account of laws is rejected.  What alternative views are there?  None that help the naturalist who thinks laws provide an ultimate explanation.  For example, early modern philosophers and scientists like Descartes and Newton regarded laws simply as divine decrees.  (I do not accept this view myself, by the way; indeed, it was intended by the early moderns as an anti-Scholastic approach to understanding nature.)  On this view, laws of nature cannot be ultimate explanations because they are merely the expression of something else, viz. God’s commands.  That -- and, of course, the theological presuppositions of this view -- make it unavailable to the naturalist looking to make laws ultimate.

How about a Platonic view of laws?  On this view laws are abstract objects that concrete physical phenomena “participate” in.  But what is it that brings it about that the phenomena participate in the laws?  And why is it these laws rather than some others that the phenomena participate in?  On this view it is not the laws themselves, but rather whatever it is that answers these questions (a Platonic demiurge?), that will be the ultimate explanation of things.  On this view too, then, laws are not available to the naturalist as an ultimate explanation (again, “brute” or otherwise).

How about a regularity view of laws?  On this Humean view, to say that it is a law that A’s are followed by B’s is just to assert a regular correlation between A’s and B’s, perhaps together with something else (such as a counterfactual conditional to the effect that had an A been present a B would have been present as well).  The trouble here is that laws so understood, whether “ultimate” or otherwise, don’t explain anything at all.  If it is the case that A’s are always in fact followed by B’s and that a B would have been present had an A been present, then to call this a “law” merely re-describes this fact, rather than making it intelligible. 

Nor does it help to say that the “law” in question is a special case of some other law, because that just relocates the problem rather than solving it.  If to say “It is a law that A’s are followed by B’s” doesn’t by itself explain anything, then it doesn’t help to say that this is a special case of a law relating C’s and D’s, if the statement “It is a law that C’s are followed by D’s” also by itself doesn’t explain anything.  And this is true no matter how far down you go, as long as what you stop with is itself just some further “brute” regularity.   The “bruteness” is not confined to the bottom level but exists all the way up and down the series.  To suppose otherwise is like supposing that a set of IOU’s counts as real money as long as you stack them high enough.  The IOU’s at the top of the stack are no more real money than the ones at the bottom are, and the higher level laws on a regularity theory are no more explanatory than the bottom “brute” level laws are.

Hence while the regularity theory might be claimed to provide an account of explanation alternative to those implied by the Aristotelian, Platonic, and theological accounts of laws, in fact it is not an account of explanation at all but, implicitly if not explicitly, the giving up of the possibility of explanation (ultimate or otherwise).  And it is hard to see what motivation there could possibly be for a theorist of laws of nature to accept it, other than as an ad hoc way of avoiding commitment to an Aristotelian, Platonic, or theological view of laws.  (Ockham’s razor is certainly not a good motivation, for Ockham’s razor is a principle of explanation, and the regularity view makes laws non-explanatory.)

So, Keith, it seems to me that your position has the following serious problem.  You want to endorse a form of naturalism according to which real explanations are possible at levels of physical reality higher than the level of the fundamental laws of nature, yet where these explanations rest on a bottom level of physical laws that have no explanation at all but are “brute facts.”  But this view is, I maintain, incoherent.  For if you endorse a regularity view of laws, then you will have no genuine explanations at all anywhere in the system.  All of reality, and not just the level of fundamental physical laws, will amount to a “brute fact.”  Whereas if you endorse instead an Aristotelian, Platonic, or theological view of laws, then you would be acknowledging that all laws of nature, including even the fundamental laws, are dependent on something else and thus cannot provide ultimate explanations -- and you would also in each case be taking on other commitments incompatible with your naturalism.

Now that’s just one problem for your position.  There are others.  For example, I would also argue (and argue at length in the book) that Humean and other objections against PSR and PC all fail.  For instance, when Humeans argue for the conceivability of something existing without a cause or explanation, and then take that to entail the real possibility of something existing without a cause or explanation, they are committing a very crude fallacy.  The most that Humean arguments show is that we can conceive of a thing without conceiving of its cause or explanation, but to conceive of A without conceiving of B simply doesn’t entail that A can really exist without B.  We can conceive of something’s being a triangle without conceiving of its being a trilateral, but any triangle must also be a trilateral; we can conceive of a man without conceiving of his height, but any actual man must have some height or other; and so forth.  (Humean arguments are problematic in other ways too, as I show in the book.)

I would also argue that PSR, rightly understood -- that is, in its Scholastic version rather than in the Leibnizian rationalist versions usually considered in contemporary discussions of the subject -- cannot coherently be denied.  Consider that whenever we accept a claim as rationally justified, we suppose not only that we have a reason for accepting it (in the sense of a rational justification), but also that our having this reason is the reason why we accept it (in the sense of being the cause or explanation of our accepting it).  We suppose that our cognitive faculties track truth and standards of rational argumentation, and that it is because they do that we believe the things we do.  But if PSR is false, then we can have no justification for supposing that any of this is really the case.  We may in fact believe what we do for no reason whatsoever, and yet it might also falsely seem, again for no reason whatsoever, that we believe things for reasons.  And our cognitive faculties may have the deliverances they do for no reason whatsoever -- rather than because they track objective truth and standards of logic -- and yet it might also falsely seem, for no reason whatsoever, that they do track the latter.

In short, either everything has an explanation or we can have no justification for thinking that anything does.  No purported middle ground position, on which some things have genuine explanations while others are “brute facts,” can coherently be made out.  If there really could be unintelligible “brute facts,” then even the things we think are not brute facts may in fact be brute facts, and the fact that it falsely seems otherwise to us may itself be yet another brute fact.  We could have no reason to believe anything.  Rejecting PSR entails the most radical skepticism -- including skepticism about any reasoning that could make this skepticism itself intelligible.  Again, the view simply cannot coherently be made out.

Finally, as to your claim, Keith, that the accounts Scholastics and others give of something’s being self-explanatory make use of “obscure” notions, I would deny that there is any good reason for this charge.  Take the Aristotelian theory of actuality and potentiality, on which is based the Scholastic thesis that God is pure actuality.  When you say that such claims “sound… like verbal formulas devised to obviate a problem rather than solve it,” that gives the impression that they are spun out of whole cloth in an ad hoc way in order to give the theist something to say in response to his critic -- as if the theist were saying:  “How can something be self-explanatory?  Hmm, er, well now, let me think… Oh, wait! How about this: A self-explanatory terminus of explanation would be one that is pure actuality!  Yeah, that’s the ticket…”

But of course that’s not at all what is going on.  The theory of actuality and potentiality was originally developed for reasons that have nothing to do with natural theology, but rather as a way of responding to Parmenidean arguments against the possibility of genuine change.  It is also a theory that is recapitulated in other contexts having nothing to do with natural theology.  For example, the revival of interest in the notions of active and passive causal powers in contemporary metaphysics and philosophy of science is largely a recapitulation of the ancient theory of actuality and potentiality (in ways I discuss in my Scholastic Metaphysics book).  If the jargon seems “obscure,” it is obscure only in the way the jargon of any philosophical or scientific theory is “obscure” -- obscure when considered in isolation and outside the context of the theory, but not at all obscure once one has studied the ideas and arguments and seen how the terminology works in its theoretical context.

Now, the same thing is true of other notions made use of to account for what would make something self-explanatory -- the essence/existence distinction, the notion of being simple or non-composite, etc.  They are not at all obscure or ad hoc but have a worked-out theoretical justification independent of their application to natural theology, though when unpacked they turn out to have theological implications.  (Scholastics would not agree, by the way, that all necessity boils down to logical necessity.  Rather, logical necessity itself presupposes metaphysical necessity.)

Anyway, I thank you again, Keith, for a very useful and civil exchange.  As per the agreed format, the last word in this first round is yours.  I will brace myself!