What are Possible Worlds? (Also, God exists)

In this video, I explain the concept of a possible world and expound on the Gale-Pruss Cosmological Argument.

[JohnnyHofmann]

I Just found this channel yesterday. I don’t regret it.

[LightoftheWorldYT]

Just wanted to say this is the greatest video ever and thank you so much for your entire channel

[kamiljan]

Hey, great video, and would like to ask ya a question, what christian philosphy books would you recommend on a beginner level? Thought about Alvin Plantinga’s shorter books or William Lane Craig learn logic and different ones. Do you have your favourites?
Thanks a lot for your work!

[twinned]

Thanks for making my brain hurt. In all seriousness awesome video.

[उस्तादGaming-mq]

Hello Sir, I have a question. 6:40 Why can't there be two worlds where, in one C is true but not E and, in Another C is true and also E.

[YovanypadillaJr]

Hey, Apologetics, I plan on buying On Guard along with two other books. Is On Guard a good book? Also, will you even go over Thomas's Five Ways?

[krzyszwojciech]

While I quite strongly lean towards the position that everything should have an explanation, I'm a bit suspicious of the possible worlds tool (I haven't studied it though, so help me out here).

The intuition that world could have been otherwise itself seems false to me in the first place (especially if there's a sufficient reason for why the world is as it is). Like, if God exists, who is omniscient about the future (or a non-God-like, deterministic First Cause exists), then the set of his attributes contains all true propositions about the future (or they can be derived deterministically in the naturalistic case). Meaning, there's only one possible world. If there's only one possible world, then our intuition about contingent propositions ("it could have been otherwise") is false and it calls into question whether this tool of logic should be used in the first place. Maybe it could still be useful despite of it, but I'm not clear on this...

Also, due to our epistemic limits, we can't necessarily conceive whether adding some proposition to the given model of the world doesn't have some far reaching, contradictory implications.

As an example, I can imagine a possible world where adding a possible explanation renders it inconsistent.
Let's assume that reality is truly indeterministic (Open Theism, or under Naturalism) and you want to tell me that there's a possible world with a possible explanation for why at the time T the atom decayed instead of not decaying (high probability of it decaying is not sufficient reason for why it in fact did decay at that time). So that leads to a contradiction.

If it is the case that adding an explanation to some feature of the world could end in contradiction, then there's a potential asymmetry there: the world without that explanation remains among possible worlds while the world with the explanation has to be removed.

[davidcates]

This is kind of a weird nitpick, but do we know that the cardinality of the set of all propositions is indeed aleph-0? Otherwise you can't lay them all out in a row. The inner math nerd is requiring that I state this question 🙃

[adrianfonseca]

First video of yours I’ve seen. I love it! Gonna have to check out the rest of your videos! God love you!

[aliuscogitabam]

not gonna lie, you lost me at C something something, naughty, something something arrows pointing to circles, something something C^e.
But I now have an infinite array that explains possible worlds which is not something I knew I needed til just now

[Nickesponja]

The assumption that "things could've been otherwise" is... just that, an assumption. There's no experiment we could do to check if it's true. This is why I find arguing in terms of possible worlds very weak. If I were keen to making up unfalsifiable hypothesis to counter valid criticism, I would just say "well what if everything is necessary and there are no other possible worlds? Then there's no problem with there being no explanation for the universe!". As I despise that tactic however I will not do that.

On another note, I've noticed that your proof doesn't at any point use the fact that e explains C. You could just as well say that e is "unicorns exist" and use the exact same proof to show that unicorns exist in our world. I'm sure there's something I'm missing here so I'd appreciate some help.

[g-km]

Wouldn't you say weak PSR entails Strong PSR?

[BSFree-esml]

NIce try.
" God exists... but I'm not going to show it in this video "

[j.victor]

Can you make a video defending the resurrection, and other about miracles?

[DeconvertedMan]

A possible world exists where I'm god, if I'm god then I exist in all possible worlds, therefor I am god in this world.
Woops!

[somerandom]

I was with you right up until you claimed the explanation was a god.

I'd love to see how you avoid the god of the gaps when you try to fill this gap in our knowledge with your god.