Greg wrote:

This week I have been looking at some of the literature from the philosophy of science on brute facts, and it seems that one Thomistic lacuna is the topic of brute facts.

Most Thomists take the illegitimacy of brute facts to be pretty obvious, whereas physicalists find it obvious that there will be some brute facts. The consensus position seems to be: Brute facts are facts that have no explanation, and some of these are inevitable. If there is a Theory of Everything, then it will be a brute fact; boundary conditions of the universe might also be brute facts. The goal of science is to achieve a "positive epistemic state" toward each fact. If a fact has an explanation, then this positive epistemic state involves learning that explanation. But if it has no explanation, then one achieves this positive epistemic state by learning that it has no explanation. Some authors call the positive epistemic state in the latter case understanding; brute facts are understandable, though inexplicable. Understanding very generally involves knowing "the place" that a fact has in the world's causal structure. (Obviously there are questions here of how one could ever learn that a fact is brute.) If it's on the "brink" of the world's causal structure (to use Ludwig Fahrbach's term), then that's all you'd need to learn, to achieve that "positive epistemic state".

How can one even in principle ascertain that a certain fact is brute? Does not very obliqueness of brute facts present one providing a justification for them (at this point I must qualify as I know some defenders of the strong PSR have offered scholia to the effect that 'either a proposition has an explanation or there is an explanation for its lacking an explanation') - if not then I want to see what such a grounds and explanation for bruteness would look like. If it's a merely negative case i.e. we cannot find an explanation, then that's no case at all - theories that fail to provide explanations are legitimately succeeded by those that do.

Greg wrote:

It's somewhat interesting that the Scholastic PSR is sometimes framed as "Being is intelligible", because physicalists, in a twisted sense, seem to hold that--if by "intelligible" you mean "understandable" in the above sense. Eric Barnes, for instance, supposes that all possible worlds are equally understandable in principle, because even in a possible world in which all facts are brute, you could understand each fact.

I wonder how one defends PSR in that context. Even Alex Pruss has done some of the deepest work doesn't, I think, attempt to address himself to a crowd like that. Of course you could just say, "I won't dispute with anyone who denies first principles." But it's a bit worrying to treat PSR as self-evident, say, when it is so readily taken for granted by so many philosophers that it can't be legitimate.

Well thus far nobody you've mentioned has provided a criticism of it; as you say substituting the question of 'why something is' with the question of 'what something is' is merely to change the subject. Pruss need offer no specific objections to such crowd - instead he ought to open by asking what their objections to the PSR are actuelly are. One might, for instance argue against them by pointing out that their use of brute facts is ad hoc - why do the boundary conditions of the universe have a more positive claim to be brute facts than, say, the diversification of species or their wallets having disappeared and reappeared in my pocket?

Greg wrote:

Which brings us to the other gap. Feser and other Thomists acknowledge, for sure, that they do not mean the same thing by "explanation" that contemporary philosophers of science do. Fair enough. Thomists mainly want to explain the existence of contingent beings, and they do so by citing the being that is causally responsible for the explanandum. Physicalists are generally interested in explaining propositions.

Well this is the difference between the 'Strong PSR' as formulated by Leibniz and the 'Weak PSR forumalated by later philosophers such as Stephen Davis and others. The Strong version was shied away from because it seemed vulnerable to issues like the Maximally Big Conjunction and Modal Collapse (though the two are really the same despite the former having a fancy sprinkling of Russell's Paradox). As far as I was aware Pruss opts to defend the stronger version.

Greg wrote:

Adopting the contemporary terminology, Thomists agree that there are brute facts--propositions that are contingent and lack a logically sufficient cause, say. For instance: free decisions (including God's willing that this world exist). So it's a debate that should be approached subtly..

Well that example is an instance of how the Strong version arguably leads to Modal Collapse isn't it? If God must create the best of all possible worlds and possibility depends on God then said world becomes the only possible world.

Last edited by DanielCC (4/10/2016 4:57 am)

iwpoe wrote:

In those terms, particularly your thought that there could be a world of only brute facts each of which is understood, seems entirely unintelligible. In terms of what principle are they all what they are? In terms of what principle are they even a plurality as opposed to a one? Etc.

Your given example also seems to be likely internally incoherent, because it's hard for me to understand how you could talk about relations between each of the brute facts so perhaps I would need more information about what a brute fact in that case is exactly supposed to be.

I am in agreement. Barnes specifically suggests that there might be a world that contains nothing but inexplicable explosions and claims that there's no contradiction involved in supposing so, which is just the usual Humean point.

I mean, I suppose they would just flatly balk at the suggestion that any account of why the explosions are what they are need be given.

iwpoe wrote:

I think most classical thinkers would be perfectly content with some merely pragmatic and epistemic understanding of a brute fact as something we have no means of knowing or even something which is contingently, though in principle, inaccessible to us- say the individual knowledge of every possible geometric figure (their being infinite, the information about them would exaust finite minds and even equipment made to process and store that information) -but if by brute fact you mean something which is of itself unintelligible- something which couldn't be known even by God, something for which there simply is no explanation - that is Magic and not permitted.

Writers distinguish between epistemically brute and ontologically brute facts. The latter are inexplicable (though not necessarily inexplicable in principle), while the latter just have no known explanation. It might be that human limitations prevent one from learning that a merely epistemically brute fact has an explanation, in which one might wrongly treat it as ontologically brute.

iwpoe wrote:

I'm also not surprised that this hasn't been well covered in recent philosophy. Pruss admits that his monograph on the PSR is the first in English in an absurdly long time. To find good thematic coverage of the topic, you'd proabably have to read Leibnitz and those following after him or cobble it together from the different places in ancient and medieval philosophy.

Yes, you're right. Hopefully someone else will take up the topic soon. I think Pruss' work is important but his treatment is generally less interested in overthrowing the deep understandings. He is still, like Leibniz and the other moderns, interested in explaining propositions rather than beings. (Although in one article he defends a weak, propositional PSR and mounts a cosmological argument from the existence of contingent beings, which somewhat bridges the gap.)

Last edited by Greg (4/10/2016 11:23 am)

iwpoe wrote:

What exactly *is* the problem with Modal Collapse supposed to be, Daniel? I've always had a hard time seeing it.

PSR says every contingent proposition has an explanation. Suppose also that explanation involves entailment.

Let p be the conjunction of all true contingent propositions. Then p is contingent. So p has an explanation, q. q is either necessary or contingent. If q is necessary and entails p, then p is necessary (so everything that is true is necessary: modal collapse--though in this formulation it's also a contradiction since p was supposed to be contingent). If q is contingent, then q is one of the conjuncts of p, so p explains itself, which is (supposedly) absurd.

Greg wrote:

Yes, you're right. Hopefully someone else will take up the topic soon. I think Pruss' work is important but his treatment is generally less interested in overthrowing the deep understandings. He is still, like Leibniz and the other moderns, interested in explaining propositions rather than beings. (Although in one article he defends a weak, propositional PSR and mounts a cosmological argument from the existence of contingent beings, which somewhat bridges the gap.)

John Edwin Gurr wrote a book on The Principle of Sufficient Reason in Some Scholastic Systems,1750-1900.