Neuroscience and free will

[Laird]

Wouldn't it be easier if you simply the quoted the parts that state that the definition of descriptive laws entails that no events can happen out of necessity?

It's not stated explicitly in that essay, it's simply implicit in that it's pretty much the point of his argument - or rather, I took it to be implicit. But here are some quotes from his book which suggest that there is a middle ground between a thoroughgoing descriptivist view and a thoroughgoing prescriptivist one which he calls "Necessitarianism". The quotes in any case seem generally relevant:

I have lived for many years with the problems I discuss in this book. I have, over those years, wrestled with and vacillated between two competing theories, Necessitarianism and Regularity. But, during the last few years, I have finally settled on the latter. In what follows, I try to defend Regularity against Necessity.

The Regularity Theory might best be thought to be a negative theory. It is the theory that there is no natural necessity, either in re or in physical laws. Regularists, that is, deny natural necessity in both its forms and under all its names: “causal,” “ontic,” “nomological,” “etiological,” or what have you.

The Regularity Theory [...] want{s} to ‘locate’ the truth-conditions of physical laws wholly in the events of the world’s unfolding history and in the states actually instanced. Again aphoristically, this may be stated by saying that physical laws are ‘descriptive’ of what is and of what happens.

The Necessitarian view, while also advertising itself as a descriptive (as opposed to prescriptive) account, assigns to physical laws a different logical-cum-ontological status. Rather than it being physical laws that take their truth from what happens, it is something of the other way around: It is the physical laws that set the bounds on what can and cannot occur. For the Necessitarian, there is some sense in which physical laws have ‘primacy’ over mere occurrences. Laws impose ‘constraints’ on the way the world is and on what occurs therein.

Necessitarianism shares with the Regularity Theory the thesis that physical laws are descriptions; but it also shares with the Prescriptivist Theory the view (just mentioned) that physical laws are irreducible to statements about what happens; physical laws are statements about what can or must occur.

Perhaps, Paul, you are a Necessitarian.

I suppose you might call those "laws," but I would tend to call them "scripts."

That's fine - as you know we've already agreed not to refer to them as "laws" but rather to encompass both under the generic term "generalised conditional descriptions of events".

That "it's possible that we could have a law that describes events that must happen a certain way in all possible worlds"? Because there may be events that follow logically and inexorably from their precursors and logic holds in all possible worlds.

For a law to be necessary, it's not logic that needs to hold in all possible worlds, it's the law itself. So, can you give me an example of a law that holds in all possible worlds? To be clear on what that means: it means that neither of us (nor anybody else) can conceive of a logically coherent world in which the law does not apply. So, let's say you pick "the law of gravity" - that would be a non-starter because I'm sure you can conceive of a world in which the law of gravity as we know it in this world did not exist, either because there was no gravity at all or perhaps because it was inversely proportional to the cube of the distance between the centres of the attracted masses rather than to the square.

So, go for it - see if you can come up with an example...

How can we possibly know that there are no such events?

For an event (whether associated with a law or not) to be necessary, again the criteria is that the event occurs in every possible world. Again, this means that no logically coherent world is conceivable in which the event does not occur. So, again - see if you can come up with an example of such an event...

I disagree. I think you are endowing the choice between prescriptive and descriptive laws with power that it does not have. We can't say "I don't think there are any events that happen out of necessity" and then assign a name to this idea and then argue that since the name means "laws just describe events" therefore there are no events that happen out of necessity. This appears to be the argument.

That's not the argument for why there aren't any events that happen out of necessity; that argument is independent of whether laws are prescriptive or descriptive, but since there seems to be a possible middle ground between the two, let's drop that discussion and focus instead on the more fundamental question: are there any necessary laws and/or events in/of the empirical world?

Your claim seems to be that there could be.

You cited a paper which claims that there are (necessary laws), but you didn't read it. I did, and its ultimate argument/claim was awful (there were a lot of good bits along the way though). Basically, the author claims that laws are necessary because... they can be defined to be. You can read the paper for yourself to see though.

But we should realize that the claim about events is a just-so claim. We have no evidence that no events happen out of necessity.

I would call that second statement a just-so claim itself...

So why don't we do that so we can continue? I will stipulate that we are operating under the Descriptive Model of the Universe and no event ever happens out of necessity.

My intention in starting this exchange wasn't for you to stipulate anything, it was for you to state whether you actually agree. You're of course not obliged to respect my intention though.

In any case, I think better is to do as I suggested above: instead consider explicitly the more fundamental question of whether there are any necessary laws and/or events in/of the empirical world.

Laws are the same things as underlying reasons only if we endow laws with some sort of magical causal abilities.

That's not a good reason for making the distinction: "underlying reasons" have no more causal ability than do "laws"...

What do you mean when you say that a descriptive law is contingent?

I mean that there is a possible world in which it does not exist/obtain.