Monday, September 26, 2011

A Leibnizian Kalam Argument?

Staying with my recent approach of tossing up new arguments and seeing what sticks, I thought I'd give this a try. I've defended several modal cosmological arguments before, but this time I want to take some Leibnizian and kalam considerations into account.

1. Possibly, everything that exists has an explanation of its existence, either in the necessity of its own nature or in an external cause. (Premise, W-PSR)

2. Necessarily, whatever begins to exist is contingent. (Premise)

3. Possibly, the universe began to exist. (Premise)

4. Possibly, the universe is contingent. (From 2 and 3)

5. Hence, the universe is contingent. (From 4 and S5)

6. Possibly, whatever is contingent has an external cause. (Premise, implied by W-PSR)

7. Possibly, the universe has an external cause. (From 5 and 6)

8. Necessarily, if the universe has an external cause, that cause is a timeless, changeless, immaterial, and very powerful first cause. (Premise)

9. Possibly, a timeless, changeless, immaterial, and very powerful first cause exists. (From 7 and 8)

10. Necessarily, a first cause is either necessary or contingent. (Definition)

11. Necessarily, a first cause cannot be explained by anything else. (Premise)

12. Necessarily, a first cause is explained by a necessity of its own nature. (From 1 and 11)

13. Therefore, a timeless, changeless, immaterial, and very powerful first cause exists. (Implied by 12)


  1. Always wondered about this. Seems to make sense to me. Wonder what Craig and others would say about it..

  2. I think it may even be possible to drop the modal aspect and give a typical kalam defense for the finitude of the universe and change 3 to the universe began to exist, 4 then becomes the universe is contingent (2 and 3). Do you think that works? Or does that simplify too much and cause some of the power here to be lost?

  3. Hi Michael,

    Although I agree with the arguments that purport to show the universe's finitude, I wanted to weaken the premises to the point where even the most ardent skeptic would most likely accept them. I figure if one doesn't accept the claim that the universe began to exist, then he may at least accept it as a possibility.

  4. Gotcha. Makes sense. What about those who dislike S5? Suggestions?

  5. S5 really isn't controversial, but the modal third way is an example of a modal argument that doesn't necessarily use S5.

  6. Ok. I have some professors at UC that talk of S5 as if it's a made up language and not good logic lol then again, this is coming from a university that refuses to hire a logician... haha

  7. Oh wow haha. Sometimes detailing the inverse operation of S5's "possibly necessary, therefore necessary" is a good way of showing its truth. "Possibly not necessary, therefore not necessary" is rather obviously true, since if there is a possible world at which X does not exist (per the antecedent) it follows that it does not exist in all possible worlds (per the consequent).

    Moreover, necessities don't vary from one possible world to another. We know that a married bachelor cannot exist in any possible world because it's impossible for such an entity to exist in the actual world.

    Plus, all languages are made up. ;)

  8. That's part of the problem. We have Chris Gauker, who is essentially a linguist in the like of Wittgenstein, and he holds that words give our minds thoughts rather than the other way around, or something along those lines. Basically, words give our sentences meaning, so an externalist account of language, rather than an internalist account. So I believe where some of our professors stand is that S5 is internalistic or something? It's confusing, and wrapping my head around Gauker's work is a mighty task lol

  9. It's definitely worth studying these alternative theories of language, despite my misgivings about externalist accounts and, on a somewhat tangential note, non-correspondence theories of truth. William Alston's "A Realist Conception of Truth" is a good read in favor of the more traditional view.