How do we know what is possible (what can be true)?

[Ripheus27]

Although I'm a Christian, I owe this self-ascription less to outright belief in the actual existence of God and the actual truth of the Resurrection than I owe it to the combination of the following two beliefs:

(1) To prove that something is possible in concrete reality (and not just in the domain of pure metaphysical abstraction) requires substantially more than just imagining or conceiving that thing's existence. That is, conceivability/ability to be imagined ≠ ability to exist.

(2) It is possible to prove that God/the Resurrection are possible.

If I only believed (2), I might not be anything different from the average agnostic or even atheist. (However, some theists argue that if God is necessarily possible, then God is actually necessary, wherefore an atheist would be put upon in a debate with such people to even deny possibility of God.) Because of (1), though, I think my position might be thought of as neither theistic nor atheistic but transtheistic.

Now for the rest of the point of the thread: what standards do you use when judging that something might be true? How many forms of "might be" do you work with?

 

[Ken-1122]

Although I'm a Christian, I owe this self-ascription less to outright belief in the actual existence of God and the actual truth of the Resurrection than I owe it to the combination of the following two beliefs:

(1) To prove that something is possible in concrete reality (and not just in the domain of pure metaphysical abstraction) requires substantially more than just imagining or conceiving that thing's existence. That is, conceivability/ability to be imagined ≠ ability to exist.

(2) It is possible to prove that God/the Resurrection are possible.

If I only believed (2), I might not be anything different from the average agnostic or even atheist. (However, some theists argue that if God is necessarily possible, then God is actually necessary, wherefore an atheist would be put upon in a debate with such people to even deny possibility of God.) Because of (1), though, I think my position might be thought of as neither theistic nor atheistic but transtheistic.

Now for the rest of the point of the thread: what standards do you use when judging that something might be true? How many forms of "might be" do you work with?

What does it mean to be "necessarily possible"?

K

 

[Ripheus27]

What does it mean to be "necessarily possible"?

Maybe I misspoke... Here's what I was trying to refer to (from Ontological Arguments (Stanford Encyclopedia of Philosophy)):

The “victorious” modal ontological argument of Plantinga 1974 goes roughly as follows: Say that an entity possesses “maximal excellence” if and only if it is omnipotent, omnscient, and morally perfect. Say, further, that an entity possesses “maximal greatness” if and only if it possesses maximal excellence in every possible world—that is, if and only if it is necessarily existent and necessarily maximally excellent. Then consider the following argument:

1. There is a possible world in which there is an entity which possesses maximal greatness.
2. (Hence) There is an entity which possesses maximal greatness.

Under suitable assumptions about the nature of accessibility relations between possible worlds, this argument is valid: from it is possible that it is necessary that p, one can infer that it is necessary that p. Setting aside the possibility that one might challenge this widely accepted modal principle, it seems that opponents of the argument are bound to challenge the acceptability of the premise.


And, of course, they do. Let's just run the argument in reverse.

1. There is no entity which possesses maximal greatness.
2. (Hence) There is no possible world in which there is an entity which possesses maximal greatness.

Plainly enough, if you do not already accept the claim that there is an entity which possesses maximal greatness, then you won't agree that the first of these arguments is more acceptable than the second. So, as a proof of the existence of a being which posseses maximal greatness, Plantinga's argument seems to be a non-starter.

Perhaps somewhat surprisingly, Plantinga himself agrees: the “victorious” modal ontological argument is not a proof of the existence of a being which possesses maximal greatness. But how, then, is it “victorious”? Plantinga writes: “Our verdict on these reformulated versions of St. Anselm's argument must be as follows. They cannot, perhaps, be said to prove or establish their conclusion. But since it is rational to accept their central premise, they do show that it is rational to accept that conclusion” (Plantinga 1974, 221).

It is pretty clear that Plantinga's argument does not show what he claims that it shows. Consider, again, the argument: “Either God exists, or 2+2=5. It is not the case that 2+2=5. So God exists.” It is just a mistake for a theist to say: “Since the premise is true (and the argument is valid), this argument shows that the conclusion of the argument is true”. No-one thinks that that argument shows any such thing. Similarly, it is just a mistake for a theist to say: “Since it is rational to accept the premise (and the argument is valid), this argument shows that it is rational to accept the conclusion of the argument”. Again, no one thinks that that argument shows any such thing. But why don't these arguments show the things in question? There is room for argument about this. But it is at least plausible to claim that, in each case, any even minimally rational person who has doubts about the claimed status of the conclusion of the argument will have exactly the same doubts about the claimed status of the premise. If, for example, I doubt that it is rational to accept the claim that God exists, then you can be quite sure that I will doubt that it is rational to accept the claim that either 2+2=5 or God exists. But, of course, the very same point can be made about Plantinga's argument: anyone with even minimal rationality who understands the premise and the conclusion of the argument, and who has doubts about the claim that there is an entity which possesses maximal greatness, will have exactly the same doubts about the claim that there is a possible world in which there is an entity which possesses maximal greatness.

 

[Ken-1122]

Hey I've got one:
1) There is a possible world where money grows on trees
2) Thus, money grows on trees

K

 

[Ripheus27]

Hey I've got one:
1) There is a possible world where money grows on trees
2) Thus, money grows on trees

K

Kinda like Gaunilo (not sure what his full name was, or even if I've spelled this part of the name right) and the "perfect island"?

 

[quatona]

Now for the rest of the point of the thread: what standards do you use when judging that something might be true?

Depends entirely on the subject.

How many forms of "might be" do you work with?

Basically two:
Those that I´ll let affect my decisions ("maybe"), and those that I won´t let affect my decisions ("might be").
Exceptional claims (particularly such about allegedly existing entities that are defined ex negativo - like "supernatural") typically fall in the second category.

 

[Ken-1122]

Now for the rest of the point of the thread: what standards do you use when judging that something might be true?

If it makes sense to me.

How many forms of "might be" do you work with?

Countless

K

 

[Crandaddy]

I distinguish logical possibility from metaphysical possibility. Metaphysically possible entities/states of affairs/worlds comprise a subset of all logically possible entities/states of affairs/worlds.

For example, there seems to be a (logically) possible world in which everyone is forced to endure hellish torment for all of eternity with no hope of escape, since it seems there might be (i.e. that it is metaphysically possible for there to be) a logically-consistent world-sized set of propositions describing such a world, but I don't think such a world is metaphysically possible because I think creating it would be contrary to God's loving nature.

One area where I've run into some problems with this is that of miracles (if miracles are understood to be violations of laws of nature, that is). Is it metaphysically possible for a law of nature to be violated?

Say, for example, that I take a lead weight and throw it out into a lake. Now say that instead of sinking to the bottom as it should, the weight "floats" on the surface of the water. Assume that no natural physical mechanism is preventing the weight from sinking. Is the object I've thrown really floating?

I answer thusly:

Either

1. If the object is truly floating, then it has been altered in some way. For although it seems to be (metaphysically) possible for an exhaustive set of propositions describing the object's being spatially located atop the water (in a manner consistent with floating) to be logically consistent, it does not seem to be metaphysically possible for the unaltered weight to truly float, since it is proper to the nature of the object to sink.

or

2. If the object is unaltered, then it is not truly floating, but only appears to be floating, as per the above reasoning.

(I am assuming here that laws of nature are grounded in the natures of substances, as per a broadly Aristotelian moderate realism.)

 

[FatalHeart]

Well, since I was born only a little while ago, I tend to think of everything as possible, and that I'm just on a journey learning why and what those things are. I also believe that I matter, otherwise I wouldn't be here, or there would be no point to reason, so... This has led me to be both humble and not too unquestioning of my ability to know things. I do see logic as superior because if it were not superior, that would still be superior in a logical way. Therefor, I also think that if there is anything to know or worth knowing, it is knowable. I see life as something good, so I aim first at comfortable assumptions at how things should be, but, I am not so arrogant to assume my own thinking is all there is, and so, I look for variances in the principles I find because why assume what is best instead of really finding what is best? However, I also am on guard at being too comfortable, as I recognize that I can be wrong. This leads me to take on many different avenues of other people's revelations, and not just my own. Though, I have found that most of the time, mine works better for me. In the end i have had to accept many things that are true, even if they aren't comfortable, as I would honestly, even if I truly found that I myself do not matter, and reasoning is useless. But I have yet to find this. Most evidence points against it. I am rewarded by my honest search of truth and my humility to see things in not only my own way. My life is good and I do much good i.e. I make many people feel like they matter and treat others the same way. However, I will say, to finalize my answer to your question, if something does not change regardless of my desires, it is true. This is the final step in how I judge everything. First what logic says: is it possible, workable, without too many "absurdities," i.e. reasonable efforts needed to be made to say it is, after all, you can't bleed yourself dry on anything. Second, is it good: does it benefit, make happy, bless, uphold what it stands for, as in, just because it could be true, doesn't mean it pleasant. Thirdly, does it change according to my desires. if something is seen as logical but not good, I may fight it, if it hurts too much to accept, but after a good fight with the emotions comes the inevitable conclusion that it is true, or, that, thankfully, it isn't. But the only way to be able to rest on a conclusion is to have dealt with it internally with all integrity, because some things hurt, but, alas, they are true.