Derek Parfit 1942-2017
A reader asked me to clarify Derek Parfit’s distinction—made in my last post—between a local and a cosmic possibility. Here are Parfit’s exact words on the distinction:
“It will help to distinguish two kinds of possibility. Cosmic possibilities cover everything that ever exists, and are the different ways that the whole of reality might be. Only one such possibility can be actual, or the one that obtains. Local possibilities are the different ways that some part of reality, or local world, might be. If some local world exists, that leaves it open whether other worlds exist.” ~ Derek Parfit, (“Why Anything? Why This?” London Review of Books, Vol. 20 No. 2 · 22 January 1998, pages 24-27.)
I don’t find this distinction completely clear. The local could refer to a part of reality—like a planet—and the cosmic to the whole of reality—the universe. Alternatively, the local could refer to a particular universe and the cosmic to all the universes or the multiverse. I favor the latter interpretation. Either way, the cosmic possibilities are what is most important.
As I said in my previous post regarding Parfit’s position:
The cosmic possibilities range from every conceivable reality existing (the all worlds possibility) to no conceivable reality existing (the null hypothesis). In between there are an infinite number of possibilities such as: only good universes exist, only 58 universes exist, only worlds that obey string theory exist, only bad worlds exist, etc. Of all these cosmic possibilities at least one of them must obtain. So the question is, which one and why?
… Parfit concludes that the null hypothesis is the simplest, the all worlds hypothesis the fullest, the axiarchic hypothesis the best, and so on. Now Parfit wonders if a cosmic possibility obtains because it has a special feature like fullness or simplicity or goodness. What if that feature chooses reality? If it does Parfit calls it a “selector.”
… Of course, this raises the question of whether there is some deeper explanation of why there is one selector rather than another. Is there a meta-selector and a meta-meta-selector ad infinitum? Parfit acknowledges that the ultimate selector would have to be a brute fact—to stop the infinite regress—but that this is better than no explanation at all. But Parfit also believes that the simplest explanatory possibility at the meta-level is that there is no selector! This does not mean there would be nothingness—that would be a special outcome best explained by simplicity as the selector. Rather, no selector leads to a mediocre universe with nothing special about it—the way things turned out would be random. “Reality is neither a pristine Nothing nor an all-fecund Everything. It’s a cosmic junk shot.” (Holt, 236)
If it wasn’t clear from our previous post, Parfit thinks our reality is most consistent with there being no selector. And at the meta-level the no selector hypothesis is most likely because that’s the simplest hypothesis. So simplicity -> no selector -> lots of generic possibilities.
Here is how I would summarize, in the simplest way possible, the issue of why there is something rather than nothing.
Reality either has a cause, reason, or explanation (CRE) or it doesn’t. If it doesn’t have a CRE then reality is unintelligible, a brute fact or eternal. If it has a CRE then either it is its own CRE or its CRE is something else. This something else—god, aliens, other universes—is in turn either its own CRE or its CRE is something else, ad infinitum. So this chain of CRE is either infinite or something is its own CRE. As for reality being infinite, this is consistent with reality having no CRE, being its own CRE, or having its CRE be something else. So whether the reality is beginningless or not doesn’t affect our question.
Think of it this way. If you are told that reality has no CRE are you satisfied? No. You think there must be a CRE because normally things have CREs. If you are told that reality explains itself are you satisfied? No. Because normally things don’t explain themselves. If you are told that reality is explained by something else are you satisfied? No. Because now you need an explanation of that thing. For of that thing you can always ask “what is the CRE for that?” And the only answer to that question is: a) it has no CRE; or b) it is its own CRE; or c) its CRE is something else. And then you are back where you started.
In the end, our minds can’t seem to penetrate this mystery. And so we go on living.