Why anything? Why this?
Derek Parfit concludes his essay on the Universe
In the first half of this essay, I suggested how reality’s deepest features might be partly explained. Of the countless cosmic possibilities, or ways that reality might be, a few have very special features. If such a possibility obtained, that might be no coincidence. Reality might be this way because this way had this feature. Thus, if nothing had ever existed, that might have been true because it was the simplest way for reality to be. And if reality is maximal, because all possible local worlds exist, this may be true because it is the fullest way for reality to be. The highest law may be that being possible, and part of the fullest way reality might be, is sufficient for being actual.
If some cosmic possibility obtains because it has some special feature, we can call this feature the Selector. If there is more than one such feature, they are all partial Selectors. Just as there are various cosmic possibilities, there are various explanatory possibilities. For each of these special features, there is the explanatory possibility that this feature is the Selector, or is one of the Selectors. Reality would then be the way it is because, or partly because, this way had this feature.
There is one other explanatory possibility: that there is no Selector. If that is true, it is random that reality is as it is. Events may be in one sense random, even though they are causally inevitable. That is how it is random whether a meteorite strikes the land or the sea. Events are random in a stronger sense if they have no cause. That is what most physicists believe about some features of events involving sub-atomic particles. If it is random what reality is like, the Universe not only has no cause. It has no explanation of any kind. This claim we can call the Brute Fact View.
Few features can be plausibly regarded as possible Selectors. Though plausibility is a matter of degree, there is a natural threshold to which we can appeal. If we suppose that reality has some special feature, we can ask which of two beliefs would be more credible: that reality merely happens to have this feature, or that reality is the way it is because this way has this feature. If the second would be more credible, this feature can be called a credible Selector. Return, for example, to the question of how many possible local worlds exist. Of the different answers to this question, all and none give us, I have claimed, credible Selectors. If either all or no worlds existed, that would be unlikely to be a coincidence. But suppose that 58 worlds existed. This number has some special features, such as being the smallest number that is the sum of seven different primes. It may be just conceivable that this would be why 58 worlds existed; but it would be more reasonable to believe that the number that existed merely happened to be 58.
There are, I have claimed, some credible Selectors. Reality might be some way because that way is the best, or the simplest, or the least arbitrary, or because its obtaining makes reality as full and varied as it could be, or because its fundamental laws are, in some way, as elegant as they could be. Presumably there are other such features, which I have overlooked.
In claiming that there are credible Selectors, I am assuming that some cosmic and explanatory possibilities are more probable than others. That assumption may be questioned. Judgments of probability, it may again be claimed, must be grounded on facts about our world, so such judgments cannot be applied either to how the whole of reality might be, or to how reality might be explained.
This objection is, I believe, unsound. When we choose between scientific theories, our judgments of their probability cannot rest only on predictions based on established facts and laws. We need such judgments in trying to decide what these facts and laws are. And we can justifiably make such judgments when considering different ways in which the whole of reality may be, or might have been. Compare two such cosmic possibilities. In the first, there is a lifeless Universe consisting only of some spherical iron stars, whose relative motion is as it would be in our world. In the second, things are the same, except that the stars move together in the patterns of a minuet, and they are shaped like either Queen Victoria or Cary Grant. We would be right to claim that, of these two possibilities, the first is more likely to obtain.
In making that claim, we would not mean that it is more likely that the first possibility obtains. Since this possibility is the existence of a lifeless Universe, we know that it does not obtain. We would be claiming that this possibility is intrinsically more likely, or that, to put it roughly, it had a greater chance of being how reality is. If some possibility is more likely to obtain, that will often make it more likely that it obtains; but though one kind of likelihood supports the other, they are quite different.
Another objection may again seem relevant here. Of the countless cosmic possibilities, a few have special features, which I have called credible Selectors. If such a possibility obtains, we have a choice of two conclusions. Either reality, by an extreme coincidence, merely happens to have this feature, or – more plausibly – this feature is one of the Selectors. It may be objected that, when I talk of an extreme coincidence, I must be assuming that these cosmic possibilities are all equally likely to obtain. But I have now rejected that assumption. And, if these possibilities are not equally likely, my reasoning may seem to be undermined.
As before, that is not so. Suppose that, of the cosmic possibilities, those that have these special features are much more likely to obtain. As this objection rightly claims, it would not then be amazing if such a possibility merely happened to obtain. But that does not undermine my reasoning, since it is another way of stating my conclusion. It is another way of saying that these features are Selectors.
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[*] Of several discussions of these questions, I owe most to John Leslie’s Value and Existence (1979), and to Robert Nozick’s Philosophical Explanations (1981); then to Richard Swinburne’s The Existence of God (1979), John Mackie’s The Miracle of Theism (1982), Peter Unger’s article in Mid-West Studies in Philosophy, Volume 9 (1989), and some unpublished work by Stephen Grover.