We can think of the optimalist theory of ultimate explanation as the claim:
- Necessarily, that reality is for the best explains everything.
(I won’t worry in this post about two details. First, whether “reality” in (1) includes the principle of optimality itself—Rescher has suggested that it does, since it’s for the best that everything be for the best. Second, whether “reality” is all the detail of the world, or just the “core” of the world—the aspects not set by indeterministic causation.)
Given that only truths explain, (1) entails:
- Necessarily, reality is for the best.
Notice that one could accept (2) without accepting (1). One might, for instance, be a Leibnizian and think that there is a two-fold structure to ultimate explanation: first, God’s existence is explained by the ontological argument and, second, God creates the best contingent reality. On this account everything is for the best, but that everything is for the best is not the ultimate explanation, because it does not explain why God exists. Or one might think that reality is necessary and brute, and it brutely has to be like it is. And as a very suprising but non-explanatory matter of fact the way it is is in fact optimal.
I am emphasizing this, because I want to problematize (1). Grant (2). Why should we think that the fact that everything is for the best in fact explains everything?
Suppose that modal fatalism is true, and that it so happens that reality is exactly mid-way between the worst and the best possibility, and is in the only option mid-way between the worst and best. (I assume one can talk of options for reality even given modal fatalism. Otherwise, optimalism falls apart. The “options for reality” may be something like narrowly logically possible worlds.) Then:
- Necessarily, reality is exactly middling.
Now suppose a “mediocritist” said: “And that reality is necessarily exactly middling explains why reality is what it is.” But why would we buy that? Or suppose that reality is necessarily the only one that is exactly 56.4% of the way up between the worst and the best (where worst would count as 0% of the way up and best as 100%)? Surely we wouldn’t conclude that its being exactly at 56.4% explains why it is the way it is. But if not, then why should its being at 50% explain it, as on mediocritism, or its being at 100% explain it, as on optimalism?
I think what the optimalist ought to say at this point is that analogously to non-Humean pushy laws of nature, there are non-Humean pushy laws of metaphysics. One of these laws is that everything is for the best. It is the pushiness of this metaphysical law that explains reality. But there is something rather odd about pushy laws prior to all beings—they seem really problematically ungrounded.
Dr. Pruss, how do you see the Millerian cosmological argument in favor of the existence of God, which does not need to presuppose the PSR (in reality he seeks to prove something like the PSR from the principle of non-contradiction)
ReplyDeletehttps://philarchive.org/rec/FLYTMC
It looks pretty much like the Thomistic argument for the PSR that I explore in a chapter of my PSR book. I am glad the argument is getting a hearing. The way I see it, the basic problem that leads to positing a cause is that there cannot be interdependent entities, each of which presupposes the other.
DeleteDr. Pruss, under the model of modal fatalism, how would you gauge the spectrum (which is metaphysically impossible, if there are no non-actualized possibles) between what is presumed to be the best possibility for the universe, or the worst? Would a Leibnezian be inclined to propose an axiom between which this middle-ground is the perfect ground for contingent facts?
ReplyDelete1. Under the model of modal fatalism, the set of all possible worlds contains exactly one member, which is the world.
2. Leibnizian theory posits that this world is selected because it is the "perfect ground" or the best of all possible outcomes.
C. Therefore, under a fatalist-Leibnizian model, the "best" possiblity and the "only" possibility are identical, rendering the spectrum between best and worst logically impossible.
The usual move for the Leibnizian is to distinguish metaphysical possibility and narrowly logical possibility. Only one world is metaphysically possible, but many are narrowly logically possible, with only the best one being metaphysically possible.
ReplyDeleteThis reminded me of a plotpoint of the anime Fullmetal Alchemist, where the world of the show follows certain principles intrinsic to the world, in an axiarchist sense, such as the rule of equivalent exchange where to gain something one must give up something of equal value.
ReplyDeleteI now wonder whether or not such a world would be a metaphysically possible world independent of optimalist or axiarchist concers, possible even under theism - perhaps we could explain its possibility by natural law being similar but different in that it includes such principles it doesn't include in our world?