blog.kennypearce.net

Lange on the Natural Necessity of Something

Marc Lange's contribution to The Puzzle of Existence, begins with this remark:

I read recently about a baby who was trapped during the night of February 26, 2011, in a locked bank vault in Conyers, Georgia. Naturally, I wondered why that had happened (235).

In the article which follows this fantastic opening, Lange appeals to the theory of necessity and laws of nature from his 2009 book, Laws and Lawmakers, to argue that one can explain why there is something rather than nothing only by showing that something exists as a matter of natural necessity (or, in a qualification he makes at 246n11, showing that it is naturally necessary that something has a nonzero probability of existing). Lange begins, therefore, with a destructive line of argument, designed to show that the only candidate answers to the question why there is something rather than nothing are non-causal scientific explanations, then proceeds with the constructive project of showing how, on his theory, such an explanation can be given. It is, I think, to Lange's credit that the constructive portion of his essay is stronger than the destructive portion; the reverse is (and always has been) more often the case in philosophy.

Lange's destructive argument can be reconstructed as follows:

1. Every candidate answer to the question, 'why is there something rather than nothing?', must be a scientific explanation (238).


2. Scientific explanations obey the distinctness principle (236-237).


3. Any causal explanation of why there is something rather than nothing would violate the distinctness principle (239-240).

Therefore,

4. Every candidate answer to the question, 'why is there something rather than nothing?', must be a non-causal scientific explanation.

Every premise of this argument is false.

To Lange's credit, he does recognize that premise 1 is a substantive premise - that is, that not all (good) answers to 'why?' questions are scientific explanations. Nevertheless, all he says in defense of premise 1 is this:

I have taken for granted that in asking why there is something rather than nothing, we are demanding a scientific explanation. If an answer to this question does not have to satisfy the usual criteria of adequacy for a scientific explanation ... then I do not know what it must do. Of course, not all explanations are scientific explanations; there are explanations in mathematics, moral explanations, legal explanation, and even baseball explanations (e.g., for why a given baserunner is entitled to third base). But none of these kinds of explanations is demanded by the riddle of existence (238).

However, Lange goes on, immediately thereafter, to observe that "Some philosophers who claim to regard the riddle of existence as demanding a scientific explanation may not actually so regard it," and goes on briefly to discuss attempts at axiological explanations (explanations that say that the world exists because it is good for it to exist). Similarly, one might appeal to other kinds of teleological explanations, or the 'personal explanations' in which some philosophers believe. Furthermore, at 242n4, Lange discusses David Lewis's view that the existence of something is metaphysically necessary, and notes that on Lewis's view of explanation this does not actually explain why there is something rather than nothing. However, Lange rejects Lewis's view of explanation, and so holds that if Lewis were right about worlds, the existence of something rather than nothing would thereby be explained. Lange seems to think that this would be a scientific explanation, but it sure looks to me like a distinctively metaphysical explanation, different from anything found in natural science. So Lange does not give adequate reason for thinking that answers must take the form of scientific explanations and, indeed, there seems to be reason to suppose just the opposite. (Perhaps, though, an argument could be produced to show that, among the many candidate answers, the scientific explanations are, for whatever reason, more likely to succeed. This kind of argument would not rule the alternative answers out of court as Lange seems to want to do.)

Lange defines the distinctness principle, to which he appeals in premise 2, as follows:

If F suffices (or even helps) to constitute G's truth, then F is too close to G to help scientifically explain why G obtains (236).

The explanation of the laws of thermodynamics by statistical mechanics is a counterexample to this principle: the obtaining of the microphysical laws, together with the statistical facts about the microstates, constitute the obtaining of the thermodynamic laws and also explain their obtaining.

It seems plausible to me that Lange's distinctness principle holds for explanations of particular facts, although not for general facts like special science laws. Thus, for instance, plausibly the position and momentum of the various gas particles in the room does not explain why the air temperature and pressure are as they are. It is unclear, though, on which side of this contrast the fact that there is something rather than nothing belongs.

Premise 3 is false because Lange takes the question to be about "why there exists some contingent thing rather than no such thing" (239). But some necessary thing or things could have caused the existence of contingent things in a non-necessitating manner, such as indeterministic physical causation or libertarian free choice.

So Lange's argument that his sort of explanation is the only candidate explanation fails. But, as I said, in this piece Lange does a better job building up than tearing down, so let's turn to Lange's positive proposal.

In evaluating some of the other essays in this volume, I have discussed the extent to which the essay presupposes knowledge of the author's other work. I am less well-equipped to do this here, because I have read and thought about Lange's book fairly carefully. That said, I can say at least that the fact that it has been a few years since I read the book did not cause me any difficulty in getting through this essay.

The general idea of Lange's view is that subjunctive conditionals are to be taken as primitive and the different species of necessity are to be defined in terms of them. Possibility and contingency then get defined in terms of necessity in the usual way, and all naturally (i.e., physically or nomologically) necessary propositions count as laws of nature. What Lange argues is that it may well be the case that it is a law of nature (in his sense) that some particular entity or entities exist, and that if this were the case it would amount to a non-causal scientific explanation of why there is something rather than nothing.

The analysis of necessity in terms of counterfactuals, as it is explained in the essay, goes like this:

Take a set of truths that is "logically closed" (i.e., that includes every logical consequence of its members) and is neither the empty set nor the set of all truths. Call such a set stable exactly when every member p of the set would still have been true had q been the case, for each of the counterfactual suppositions q that is logically consistent with every member of the set. I suggest that p is a natural necessity exactly when p belongs to a "stable" set (245).

As Lange indicates in a footnote, there are some further complications discussed in the book, but the general idea is that for any species of necessity, in order to get a necessarily false consequent on a true counterfactual, you have to start with a necessarily false antecedent. Natural necessity is a species of necessity which is weaker than logical necessity (hence the logical consistency requirement).

From here, the idea is very simple: Newton thought that if absolute space did not exist, the Newtonian laws of motion would not hold. On Lange's view of laws, if one adds to this the two claims that (a) the Newtonian laws of motion are laws of nature, and (b) the existence of absolute space is logically contingent, then one gets the conclusion that it is a law of nature that absolute space exists. (Newton would not, of course, have called this a law of nature, and it is unclear - to me at least - whether Newton thought absolute space was logically contingent.) Lange thinks that, if Newtonian physics were true, then this would constitute a non-causal scientific explanation of why there is something than nothing. In fact, Newtonian physics is not true but, Lange thinks, it is nevertheless plausible, perhaps even likely, that an explanation of this general form is the correct explanation of why there is something rather than nothing.

(Cross-posted at The Prosblogion.)

Posted by Kenny at March 1, 2014 3:35 PM