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6/10/2018 8:19 pm  #1


How can we explain the S5 inference to a lay person?

S5 is terribly useful in the philosophy of religion. It allows us to move from "possibly, there is a necessary being" to "there is a necessary being". Because of this, one can make several modal cosmological arguments (every contingent thing possibly has an explanation, therefore... etc), or jump straight into ontological arguments if they prefer that, and get to the existence of a necessary being.

Problem is, how do we "popularize" this kind of argument? How do we make S5 clear to common people who are not used to it?

One way I try to do that is by putting it in these terms: it is possible that there is a being that must exist no matter what. That's what a necessary being is: it *must* exist, no matter what. If it is possible for it to exist, then it must actually exist.

Maybe we could just say "possible that there is a being that must exist given any state of affairs". I don't know.

What is your experience discussing S5 with lay people? Do they "get it"?

This is important because many people who, say, reject PSR will nevertheless accept weaker principles. And these principles coupled with S5 gives us the existence of a necessary being.

 

6/10/2018 11:10 pm  #2


Re: How can we explain the S5 inference to a lay person?

The one time I tried to use S5 on an atheist, mostly to try to force him to acknowledge that his disbelief was an actual metaphysical stance and not just the lack of one, it went pretty badly. Atheists can smell an ontological argument a mile away.

To avoid immediately setting off alarm bells, I'd say that S5 is best explained through mathematics. Is it possible that it's necessary that 2+2=4? What does it mean for 2+2=4 to be a necessary truth? That it will always be a fact in any possible world. If it is possible that it's necessary that 2+2=4, this means that there is at least one possible world for which 2+2=4 is true in every possible world, and therefore the possibility of necessity immediately entails necessity itself.

That said, I actually reject S5, and I'd suspect that anyone who has problems with PSR (I don't), is likewise going to reject S5 if the alternative leaves them in a situation where they have to accept PSR.

 

6/11/2018 12:40 pm  #3


Re: How can we explain the S5 inference to a lay person?

Hypatia wrote:

The one time I tried to use S5 on an atheist, mostly to try to force him to acknowledge that his disbelief was an actual metaphysical stance and not just the lack of one, it went pretty badly. Atheists can smell an ontological argument a mile away.

Went badly in the sense that you lost the argument, or went badly in the sense that he stopped engaging with you? Having the latter happen is frustrating, but depending on how gracious you and he are about it, you may have the better of it in the audience's eyes. And changing the mind of those in the audience is usually easier than changing the mind of the person you're arguing with.

That said, I don't know how to motivate acceptance of S5 either.

 

6/11/2018 3:21 pm  #4


Re: How can we explain the S5 inference to a lay person?

Nick wrote:

Hypatia wrote:

The one time I tried to use S5 on an atheist, mostly to try to force him to acknowledge that his disbelief was an actual metaphysical stance and not just the lack of one, it went pretty badly. Atheists can smell an ontological argument a mile away.

Went badly in the sense that you lost the argument, or went badly in the sense that he stopped engaging with you? Having the latter happen is frustrating, but depending on how gracious you and he are about it, you may have the better of it in the audience's eyes. And changing the mind of those in the audience is usually easier than changing the mind of the person you're arguing with.

That said, I don't know how to motivate acceptance of S5 either.

Badly in that we were never really having the same conversation in the first place! I think the value of the ontological argument is in conceptualizing what necessary existence actually means, and was using it primarily as a tool for clarification. Of course, apologetics are immediately confrontational, and it is difficult to even get someone to put effort into understanding what is being said when they're too busy tossing everything and the kitchen sink at it. I did ultimately get him to admit to having a metaphysical position, though, even if it took a fair amount of out-right bullying to get there.

I'm actually on fairly good terms with this particular atheist now, but I don't expect him to really budge at all. Theism (or anything besides materialism) is so out of sync with the dominant metaphysical picture right now that I have no idea how to get people to even step outside of their worldview enough to recognize the factors that are influencing it.

 

6/19/2018 5:42 pm  #5


Re: How can we explain the S5 inference to a lay person?

Hypatia wrote:

The one time I tried to use S5 on an atheist, mostly to try to force him to acknowledge that his disbelief was an actual metaphysical stance and not just the lack of one, it went pretty badly. Atheists can smell an ontological argument a mile away.

To avoid immediately setting off alarm bells, I'd say that S5 is best explained through mathematics. Is it possible that it's necessary that 2+2=4? What does it mean for 2+2=4 to be a necessary truth? That it will always be a fact in any possible world. If it is possible that it's necessary that 2+2=4, this means that there is at least one possible world for which 2+2=4 is true in every possible world, and therefore the possibility of necessity immediately entails necessity itself.

That said, I actually reject S5, and I'd suspect that anyone who has problems with PSR (I don't), is likewise going to reject S5 if the alternative leaves them in a situation where they have to accept PSR.

 
Rejecting S5?

Absolutely haraam

     Thread Starter
 

6/19/2018 7:10 pm  #6


Re: How can we explain the S5 inference to a lay person?

It appears that Pruss and Rasmussen's new book have a chapter on this.

 

6/19/2018 11:12 pm  #7


Re: How can we explain the S5 inference to a lay person?

Miguel wrote:

Hypatia wrote:

The one time I tried to use S5 on an atheist, mostly to try to force him to acknowledge that his disbelief was an actual metaphysical stance and not just the lack of one, it went pretty badly. Atheists can smell an ontological argument a mile away.

To avoid immediately setting off alarm bells, I'd say that S5 is best explained through mathematics. Is it possible that it's necessary that 2+2=4? What does it mean for 2+2=4 to be a necessary truth? That it will always be a fact in any possible world. If it is possible that it's necessary that 2+2=4, this means that there is at least one possible world for which 2+2=4 is true in every possible world, and therefore the possibility of necessity immediately entails necessity itself.

That said, I actually reject S5, and I'd suspect that anyone who has problems with PSR (I don't), is likewise going to reject S5 if the alternative leaves them in a situation where they have to accept PSR.

 
Rejecting S5?

Absolutely haraam

Eh, I'm actually fine with collapsing "it's possible that it's necessary that P" into "it's necessary that P," but I don't think this actually solves anything. How can we establish that something is possibly necessarily true? That seems to entail proving that it is not impossible that it is necessary, and without being omniscient ourselves, I don't see how we're in an epistemic position to conclusively demonstrate that. This seems to me to be as much the case for potential mathematical truths as it is for PSR.

So yeah, I really don't see much of a difference between weak PSR and strong PSR. (Except perhaps that the S5 version reframes the question in a way that puts more pressure on the person denying it than the one affirming it, which I don't think inappropriate, but that doesn't really make it a different argument.)

Last edited by Hypatia (6/19/2018 11:13 pm)

 

Yesterday 11:10 am  #8


Re: How can we explain the S5 inference to a lay person?

Miguel wrote:

S5 is terribly useful in the philosophy of religion. It allows us to move from "possibly, there is a necessary being" to "there is a necessary being". Because of this, one can make several modal cosmological arguments (every contingent thing possibly has an explanation, therefore... etc), or jump straight into ontological arguments if they prefer that, and get to the existence of a necessary being.

Problem is, how do we "popularize" this kind of argument? How do we make S5 clear to common people who are not used to it?

Is your question about how one defends S5 or how one makes clear what it claims?

My own sense is that S5 is intuitively plausible. It takes some working-into to see that it is non-trivial and contestable. See van Inwagen's chapter on the ontological argument in his Metaphysics. To say p is possibly necessary is to say that in some world w accessible from the actual world, p is true in every world accessible from w. It is very natural to think that p should therefore be necessary, that p is true in every world accessible from the actual world. But to describe the case this way is also to recognize that it is something that could be denied (and something that will not turn out to be true for every modality), because it could be denied that the same worlds are accessible from the actual world as are accessible from w. (It's fair to ask whether this is the right semantics, but if one's choice of semantics determines how plausible S5 looks, that only emphasizes that there is something that requires argument here.)

If you are looking for a way to defend S5 for a popular audience, then probably the place to start is the reason why we should accept S5 anyway; say what that is, and then find some way to popularize it. Unless someone understands that S5 is non-trivial, I do not think he can gain knowledge from any theistic argument that makes use of it.

 

Yesterday 12:40 pm  #9


Re: How can we explain the S5 inference to a lay person?

Greg wrote:

Miguel wrote:

S5 is terribly useful in the philosophy of religion. It allows us to move from "possibly, there is a necessary being" to "there is a necessary being". Because of this, one can make several modal cosmological arguments (every contingent thing possibly has an explanation, therefore... etc), or jump straight into ontological arguments if they prefer that, and get to the existence of a necessary being.

Problem is, how do we "popularize" this kind of argument? How do we make S5 clear to common people who are not used to it?

Is your question about how one defends S5 or how one makes clear what it claims?

My own sense is that S5 is intuitively plausible. It takes some working-into to see that it is non-trivial and contestable. See van Inwagen's chapter on the ontological argument in his Metaphysics. To say p is possibly necessary is to say that in some world w accessible from the actual world, p is true in every world accessible from w. It is very natural to think that p should therefore be necessary, that p is true in every world accessible from the actual world. But to describe the case this way is also to recognize that it is something that could be denied (and something that will not turn out to be true for every modality), because it could be denied that the same worlds are accessible from the actual world as are accessible from w. (It's fair to ask whether this is the right semantics, but if one's choice of semantics determines how plausible S5 looks, that only emphasizes that there is something that requires argument here.)

If you are looking for a way to defend S5 for a popular audience, then probably the place to start is the reason why we should accept S5 anyway; say what that is, and then find some way to popularize it. Unless someone understands that S5 is non-trivial, I do not think he can gain knowledge from any theistic argument that makes use of it.

 
It's more about how to defend and explain S5 for a popular audience, because while S5 is seen as self-evident by a lot of people more acquainted with logic, its use can appear strange to common folk. Which is why, I think, the ontological argument never became a "popular" argument, unlike the cosmological and design arguments. If you say to a normal person that something actually is the case just because it possibly is the case, it can seem like crazy talk to them.

I guess I'd try to explain it by saying, again, that possibly necessary E is something like "it is possible that there exists a being that would have to exist in every possible state of affairs" or "possible that something that must exist no matter what, exists", something to that effect.

     Thread Starter
 

Yesterday 2:48 pm  #10


Re: How can we explain the S5 inference to a lay person?

Here is a cool way that I have been thinking about.

Preliminary points 

Possible worlds - a logically-consistent state of affairs that contain no logical contradiction.


Necessity - the trait of existing in all possible worlds. 

Contingent -  the trait of exisiting in some possible worlds.

Possible - exists in at least one possible 


Now consider this argument 

Now since the heart of S5 is that if a necessary being is possible then a necessary being must exist, we will have to defend that claim.

P1) A necessary being is possible 

P2) If a necessary being is possible, it exists in some possible world.

P3) If it exists in some possible world, it exists in all possible worlds.

conclusion: A necessary being exists in the actual world.

P1 is an assumption of S5 

P2 follows by definition of possible

P3 follows since a being that exists in at least one possible world but is also necessary then by virtue of necessity it will exist in all possible worlds.
 

Last edited by Noble_monkey (Yesterday 2:50 pm)

 

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