How on your terms do those possibilities obtain?

The same thing I've said a couple times already: by simple virtue of the fact that the world isn't strongly/causally deterministic. So, for example, we have a particle, a, in state s, and because strong determinism isn't the case, after interacting with particle b, it can be in state q or r.

After interaction with b, one of those possibilities will be what obtains in the actual world. The other we can talk about via possible world counterfactuals. It could have turned out that the other was the case instead, because there were two possibilities.

That's the simplest example. More complex examples work similarly.

One can simply posit nonmaterial particulars. — Terrapin Station

What would an example of a 'nonmaterial particular' be?

Incidentally, I find the argument for 'scholastic realism' quite persuasive, because I believe that many 'intelligible objects', including real numbers, are real - i.e. the same for anyone who can grasp them - but not material, i.e. only perceptible to the intellect.

What rational thought enables is the ability to perceive intelligible objects and relations which is what grounds speech, thought and reason in the intelligible order.

Of course this attitude it wildly unpopular in current analytic philosophy.

What would an example of a 'nonmaterial particular' be? — Wayfarer

It's difficult for me to give a descriptive example of a nonmaterial anything, because personally I don't believe that the idea of nonmaterial things makes any sense. But obviously many people don't agree with me, and some of those people can be nominalists.

If one is an idealist, where one rejects that anything whatsoever is physical/material, then any particular would do. For example, a particular rock. The idealist thinks that it's not material, not physical.

I just can't describe what the "nonmaterial" part amounts to, exactly, because that bit seems incoherent to me.

It seems to me what you’ve said there is to the effect that “possibilities obtain because there are possibilities.”

If for example there’s a possible world where the laws of physics (however you understand them) are radically different from the ones we have, how on your terms does that possibility obtain? That it’s there and we can talk about it isn’t a response I’m very willing to accept.

It's difficult for me to give a descriptive example of a nonmaterial anything, because personally I don't believe that the idea of nonmaterial things makes any sense. — Terrapin Station

But your argument, at that point, depended on it. You were arguing that one didn't have to be a materialist to be a nominalist, because you could posit a non-material particular, but when pressed as to what this might be, you can't answer the question!

If one is an idealist, where one rejects that anything whatsoever is physical/material — Terrapin Station

Idealists don't reject that things are physical and/or material; idealism can perfectly well recognise the difference between real and imaginary. What I think idealism rejects is that material things have any intrinsic reality.

It seems to me what you’ve said there is to the effect that “possibilities obtain because there are possibilities.” — AJJ

And that's certainly the case--describing what possibilities are is going to be a case of describing possibilities, right? In other words, it's basically defining what possibilities are, and that needs to be the same on both sides--the definiendum and the definiens need to amount to the same thing or it's not really a definition. We're just not repeating the word on both sides. We're explaining what it refers to just in case someone doesn't know.

What else would we be doing if we're explaining what possibilities are/how they obtain?

If for example there’s a possible world where the laws of physics (however you understand them) are radically different from the ones we have, — AJJ

As I mentioned above, I'm not a realist on laws of physics. I mentioned that most (and maybe all) nominalists are not realists on physical laws, because it's difficult to make sense out of real physical laws that are particulars. So there's no world in which literal laws of physics obtain.

You were arguing that one didn't have to be a materialist to be a nominalist, because you could posit a non-material particular, but when pressed as to what this might be, you can't answer the question! — Wayfarer

I said that it's a possible position. I gave you an example--an idealist nominalist's particular rock. I just said that I can't give you a descriptive account of what a nonmaterial anything would be (which is what you presumably wanted), because in my opinion, nonmaterial anythings are incoherent. They're not to you.

Idealists don't reject that things are physical and/or material; — Wayfarer

Ontological idealists do. I already specified that above.

I'd be surprised if you were to now claim that one can't have an ontology that rejects physical/material things wholesale.

What else would we be doing if we're explaining what possibilities are/how they obtain? — Terrapin Station

So you’ve explained that possibilities are possibilities (how things could have been), but you haven’t as far as I can tell explained how, on your terms, they obtain.

As I mentioned above, I'm not a realist on laws of physics. — Terrapin Station

I know - I addressed this by inserting the “(however you understand them)”. I’m asking about a possible world where everything behaves very differently, and how on your terms that possible world obtains.

I can try another example: If for example there’s a possible world where this planet doesn’t exist, how on your terms does that possibility obtain? The answer to the effect that it’s there and we can talk about it has been covered already.

So you’ve explained that possibilities are possibilities (how things could have been), but you haven’t as far as I can tell explained how, on your terms, they obtain. — AJJ

You'd have to explain why on your view the fact that the world isn't strongly/causally deterministic isn't an explanation for how possibilities obtain. (Or actually that should be phrased as how more than one possibility consequent to identical antecedent states obtains)

What I'm saying there is the fact that enables multiple possibilities. So why wouldn't that be an explanation? What other sort of thing would you be looking for as an explanation?

What I'm saying there is the fact that enables multiple possibilities. So why wouldn't that be an explanation? What other sort of thing would you be looking for as an explanation? — Terrapin Station

If I asked you for an explanation why it rains sometimes and you said “because there is a fact that enables there sometimes to be rain” then you’re not explaining anything - you’re just agreeing with me that there is indeed something called rain that happens sometimes.

I explain possibilities by positing abstract objects called possible worlds, with this world being a manifestation of some of them. Obviously you can’t offer the same explanation - yours must be grounded in the material world because you’ve stated you’re a nominalist and a materialist. So if there is a possible world where this planet doesn’t exist, you must appeal to something in the present world which materially contains that possibility - if there isn’t anything then it doesn’t appear you can coherently say on your terms that such a world is possible.

If I asked you for an explanation why it rains sometimes and you said “because there is a fact that enables there sometimes to be rain” — AJJ

What would be the explanation of rain that wouldn't be identical to the fact(s) that enable(s) rain?

I explain possibilities by positing abstract objects called possible worlds, with this world being a manifestation of some of them. — AJJ

On your view, isn't that the fact that makes possible worlds obtain? If so, how is that an explanation per your criteria? You're insisting that explanations are simply relaying the fact(s) that enables or amounts to what we're explaining.

What would be the explanation of rain that wouldn't be identical to the fact(s) that enable(s) rain? — Terrapin Station

Those would be identical. But saying “there is an explanation” about something (which I see what you’re doing as) isn’t the same as explaining it.

I explain possibilities by positing abstract objects called possible worlds, with this world being a manifestation of some of them.
— AJJ

On your view, isn't that the fact that makes possible worlds obtain? If so, how is that an explanation per your criteria? — Terrapin Station

It’s an explanation for how possibilities as you described them earlier obtain. All you’ve done it seems to me is describe possibilities without offering an equivalent explanation for how they obtain.

Can I take it that what you’re positing is that the existence of possible worlds is some kind of brute fact?

You'd have to explain why on your view the fact that the world isn't strongly/causally deterministic isn't an explanation for how possibilities obtain. — Terrapin Station

Just to make this clear: Saying the world isn’t “strongly/causally deterministic” is to my mind just another way of saying there are possibilities. Saying there are possibilities doesn’t explain how there are possibilities. If you’re saying it’s simply a brute fact about the world that there are possibilities then fine - I don’t think that’s an adequate way to understand things, but we don’t need to argue about that.

Saying the world isn’t “strongly/causally deterministic” is to my mind just another way of saying there are possibilities. — AJJ

So "positing abstract objects called possible worlds" isn't another way of saying there are possibilities?

So "positing abstract objects called possible worlds" isn't another way of saying there are possibilities? — Terrapin Station

It is a way of saying that, sure - but it also explains how there are possibilities: There can be a possible world where this planet doesn’t exist because the possibility is an abstract object that exists independently of the material world.

There can be a possible world where this planet doesn’t exist because the possibility is an abstract object that exists independently of the material world. — AJJ

That's just saying what a possibility is on your view.

That's just saying what a possibility is on your view. — Terrapin Station

I disagree - it’s taking an example of a possible world where this planet doesn’t exist and saying such a possibility can only exist if you’re a realist about possible worlds, i.e. it’s explaining how that possibility exists.

There can be a possible world where this planet doesn’t exist because the possibility is a factor of the material world not being thoroughly, strongly deterministic.

What is different about your formulation?

What yours amounts to is: “There can be a possible world where this planet doesn’t exist because the possibility is a factor of the material world having possibilities.”

What mine amounts to is: “There can be a possible world where this planet doesn’t exist because the possibility doesn’t depend on the material world from which we would not be able to derive that possibility.”

I'm asking not what's different about the content of the explanations, but.what's different about them structurally that makes one an explanation and the other not an explanation.

Here’s the second definition when I Google explanation: “a reason or justification given for an action or belief.”

So what your formulation amounts to structurally is: “There can be a possible world where this planet doesn’t exist [belief] because the possibility is a factor of the material world having possibilities [justification].”

Mine is the same structurally. The problem I have with yours is it doesn’t actually offer a proper justification, so what you’ve made there is an assertion rather than given an explanation.

The problem I have with yours is it doesn’t actually offer a proper justification, — AJJ

Where of course you'd need to present what a "proper justification" is supposed to amount to.

Here’s the definition you get when you Google justification: “the action of showing something to be right or reasonable.”

You haven’t in my view shown yourself to be right or reasonable on that point - rather you’ve made an assertion that you haven’t yet backed up.

As you could probably guess, I don't think that positing real abstracts is either right or reasonable. So should I say you're not offering an explanation?

As you could probably guess, I don't think that positing real abstracts is either right or reasonable. So should I say you're not offering an explanation? — Terrapin Station

You could, but that would be another assertion. I’m not asserting that you’re not providing a justification for the point under discussion - it seems to me I’ve demonstrated that.

You could, but that would be another assertion. I’m not asserting that you’re not providing a justification for the point under discussion - it seems to me I’ve demonstrated that. — AJJ

What did you do different than I did? If you're being serious, it seems weird to me that you believe you're doing anything different than I am.

What did you do different than I did? — Terrapin Station

Here’s mine again: “There can be a possible world where this planet doesn’t exist [belief] because the possibility doesn’t depend on the material world from which we would not be able to derive that possibility [justification].”

My justification gives an explanation for how the possible world obtains on my terms, i.e. I reason that it’s being an abstract object which allows it to exist because on other terms it would not be able to.

It seems to me you can condense yours down to this: “There can be possible worlds because there are possible worlds.”

Here’s a parallel example to yours to press the point: “Unicorns can exist because there are unicorns.”

You’re not giving an explanation for how possible worlds can exist on your terms, just asserting that they do without offering that explanation of how I’ve been asking for.

So in short:

Mine: “Possible worlds exist on my terms by being abstract objects which allows them to exist where on other terms they can’t.”

Yours: “Possible worlds exist on my terms because they do.”