Plantinga's modal logic version of the ontological argument

Discussion in 'Apologetical Methods' started by Whitefield, Jun 8, 2009.

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  1. Whitefield

    Whitefield Puritan Board Junior

    Because Plantinga's modal logic version of the ontological argument was mentioned in another thread, I had to look it up and refresh my memory of it. Something made me uncomfortable about it and I think I know why. If we add three words in the opening proposition ("solitary in personality") and carry them throughout, I think it has a disastrous result. The ontological argument is an a priori rational argument, so we cannot appeal to anything but reason in developing it. Limited to that arena, I don't see why proposing the one who has maximal excellence is one God .. and one Person. Before you flame me, I know that is heresy of the first order, and that is why I say the argument in this form results in disaster. So, I guess I need to be told why the addition cannot be made in the modal ontological argument.

    Here is the argument as I understand it:

    1.It is proposed that a being has maximal excellence in a given possible world W if and only if it is omnipotent, omniscient, wholly good, and solitary in personality in W; and

    2.It is proposed that a being has maximal greatness if it has maximal excellence in every possible world.

    3.Maximal greatness is possibly exemplified. That is, it is possible that there be a being that has maximal greatness. (Premise)

    4.Therefore, possibly it is necessarily true that an omniscient, omnipotent, perfectly good, and solitary in personality being exists.

    5.Therefore, it is necessarily true that an omniscient, omnipotent, perfectly good, and solitary in personality being exists. (By S5)

    6.Therefore, an omniscient, omnipotent, perfectly good, and solitary in personality being exists.
  2. Whitefield

    Whitefield Puritan Board Junior

  3. chbrooking

    chbrooking Puritan Board Junior

    With the crickets chirping, shall we declare Lance the victor?
  4. VictorBravo

    VictorBravo Administrator Staff Member

    Unless you want to wait until the end of next week when I find the time to read Plantinga. . . . ;)

    By the way, without giving it a lot of thought right now, Lance's presentation seems similar to Anshelm's, and subject to a similar criticism.
  5. steven-nemes

    steven-nemes Puritan Board Sophomore

    Plantinga never suggests that the maximally excellent being has to be (or even might be) only one in person.
  6. chbrooking

    chbrooking Puritan Board Junior

    Yes, but Lance's point, I think, attacked the arbitrariness of what is included in the premise. Forget Plantinga's statement and consider why Lance's recasting of the argument fails. Obviously, the question is not directed to presuppositionalists, since we will regard both constructions as failing.
  7. steven-nemes

    steven-nemes Puritan Board Sophomore

    No, how in any way would being only one person contribute to maximal excellence? I can see that goodness, knowledge, strength, etc., do, but how is being only one person in any way similar to the other traits?
  8. Whitefield

    Whitefield Puritan Board Junior

    This isn't my argument, but Plantinga's which to which I add three words in an attempt to show the first proposition determines the final result. Many proponents of Plantinga's ontological argument think it is immune from the criticisms leveled against Anselm's.

    -----Added 6/10/2009 at 02:54:12 EST-----

    Why not? Based on a purely rational argument (which the ontological argument is) why is the first proposition limited to only three attributes? What argument is there not to add the fourth ("solitary in personality")? I think one could argue, within the ontological arena, that singleness is greater than multitude. But if multitude is greater than singleness, then why wouldn't infinitude be the "maximally excellent"? In that case, change "solitary in personality" to "infinite in personalities." Either way, the result is the God who is proved is not the God of the Scriptures.

    -----Added 6/10/2009 at 03:22:07 EST-----

    The point of this little exercise in my head is to show that the rational/philosophical arguments for the existence of God (ontological, cosmological, teleological, and moral) cannot tell us who this "proven" concept of God is, or what He is like.
  9. steven-nemes

    steven-nemes Puritan Board Sophomore

    I don't see the connection between the number of personalities in a being an that being's excellence; I can see the connection between the goodness, power, and knowledge of a being and that being's excellence, however. I don't think the choices are arbitrary because I can plainly see that the latter traits constitute an excellent being, and no one would say that the former is even relevant to the excellence of a being.
  10. Philip

    Philip Puritan Board Graduate

    Are they supposed to? Reason can only get one to the idea that God exists. The apologist can only (pardon the mixed metaphor) lead the horse to water. Only the Holy Spirit can make him walk on it. Knowledge of who God is can only be gained by reading the Scriptures, and even then, only if one already has some idea (i.e. they are regenerate).

    Reason can only get one so far--the Holy Spirit must do the rest. Apologetics can only point to the truth, but cannot alone open blind eyes.
  11. Confessor

    Confessor Puritan Board Senior

    The unbeliever would also ask how a God who predestines people to hell can be wholly good. (In fact, a Molinist attempted to lay out a "reverse ontological argument" and a "reverse moral argument" on Facebook against me; he thought the Calvinist God was so evil.)

    All the terms in the first premise are subject to our presuppositions about the world.

    -----Added 6/12/2009 at 04:29:47 EST-----

    This is the Catholic view of faith and reason. It stresses that there really is no reason to accept revelation, except purely on faith, as something that natural reason is completely disconnected from.

    The Reformed view rather understands that man has no excuse whatsoever (including "it's not reasonable to accept revelation"), and that although the unbeliever must be led to repentance by the witness of the Spirit, it is nonetheless true that he has no rational reasons to remain in unbelief. The Holy Spirit provides a moral change, not some addition of knowledge. Otherwise those who reject the Gospel would have an excuse (contra Romans 1:20) because there would be no rational reason at all for them to accept it.

    In brief, if you tell a man that faith has to "bridge the gap," then there is no reason to accept unbelief, and thereby you are proposing a mitigated fideism, denying that man is wholly "without excuse."
  12. steven-nemes

    steven-nemes Puritan Board Sophomore

    Well even if our common notions of good preclude a God who destines some to damnation, this argument still proves that a God who is good exists; the existence of God is to me a priority for a natural theology argument, but whether or not this God is identical in character to the God I understand to exist from scripture is not immediately important to me. Once the unbeliever accepts that a good God exists, then later on, when his faith is more developed, we will perhaps refine our definition of "good" so that it is more in tune with what scripture says.
  13. Confessor

    Confessor Puritan Board Senior

    Once you establish that autonomous reasoning is permissible and ground the other person's faith on that principle, then he will not be rationally obliged in any sense to alter his definition of "good."

    I have personally seen natural theology lead to ridiculous views, such as annihilationism and of course any form of free-willism. This is because autonomous reasoning is labeled as premium. If man has the prerogative to interpret the universe at the outset, then he will have that prerogative at every point. And if he has that prerogative at every point, then he can conclude what counts as good entirely by his decision. He will be fulfilling Satan's enticement in Genesis 3:5 perfectly.

    In other words, you can only expect his faith to develop if you convince him of the authority of the Scriptures and not of himself. I don't doubt that it is possible for someone to be convinced of the ontological argument and later accept reprobation, but I would say that such can occur only by blessed inconsistency.
  14. steven-nemes

    steven-nemes Puritan Board Sophomore

    Sure he will. Consider the following argument:

    If scripture teaches X, then X is true.
    Scripture teaches X.
    Therefore, X is true.

    Surely any believer would be more than happy to believe anything that follows along those lines. The difficulty is in proving that scripture teaches X.
  15. Confessor

    Confessor Puritan Board Senior

    That syllogism presupposes that God has the prerogative to interpret reality rather than man. There is no way you could prove such a thing from natural theology, since natural theology presupposes that man has that prerogative.

    In other words, the only way a person will grant that first premise is if he eventually submits to the Bible on the Bible's own authority, which cannot be done via natural theology or an ontological argument.

    And you would be quite surprised at how many people would not really grant that first premise. I was talking to a friend who believes capital punishment is wrong, and I asked her, "If God came in this room and directly told you to kill someone, would you be obliged to do it?" She said she wasn't sure. This same girl also concedes that the Bible teaches predestination but refuses to believe it. Now, this girl is most likely unaware of the ontological argument, but nonetheless she shows that professing believers can have a lot of autonomy within them, based on their own interpretations of reality (specifically, ethics in her case: "God can't do that!" and "You can't kill anybody!") rather than on God's.

    And if you can't provide a rational reason why people should not be autonomous (even though they know it's morally wrong), then you haven't demonstrated rationally that they're without excuse, and we're back to the false Roman view on faith and reason that I outlined above.
  16. steven-nemes

    steven-nemes Puritan Board Sophomore

    That syllogism there is good enough to rationally oblige anyone to accept X. If they accept that what scripture teaches is true, then they are forced to follow the argument through to its conclusion, otherwise they are irrational in holding to not-X; if they are not willing to accept that (namely, that what scripture teaches is true), then they are not believers anyway, and what does it matter?
  17. Whitefield

    Whitefield Puritan Board Junior

    "rational" ... "irrational" ... "contradiction of 'x' and 'not-x'" ... please tell me again, which argument in classical apologetics account for such terms?
  18. steven-nemes

    steven-nemes Puritan Board Sophomore

    Well, definitions of such terms are irrelevant to whether or not the ontological argument proves the existence of a God, which I think was the topic of the discussion. But to answer your question: it seems that there are many things meant by the terms "rational" and "irrational" when used in various contexts, so I don't know what to tell you about that. As far as there being distinctions between X and non-X, these are plain and self-evident truths, anyone could admit to that. I don't see why this, however, is relevant to the topic of classical apologetics and natural theology.
  19. ChristianTrader

    ChristianTrader Puritan Board Graduate

    The ability to make a distinction between 'x' and 'not-x' is basic to meaning. One does not need a "system of apologetics" to account for such.

  20. Whitefield

    Whitefield Puritan Board Junior

    But one has to give an account for the source of such "plain and self-evident" things. The classical arguments rely upon rationality, but fail to ask the meta-question: "Whence this rationality which is relied upon so heavily."

    And whose meaning is the law of contradiction basic to?
  21. Confessor

    Confessor Puritan Board Senior

    My point is they will not be logically obliged to accept premise 1 unless they drop their autonomy, since premise 1 is essentially a relinquishment of autonomy, an understanding that God alone has the authority to interpret the world.

    Or, In other words,, if they accept premise 1, it will not have followed from natural theology.

    -----Added 6/13/2009 at 07:48:56 EST-----

    No, no one is obliged to "give an account" for such things, simply because they're already rationally warranted in believing it. You wouldn't tell a seven-year old kid, "No son, you can't speak as if the logical law of identity and law of contradiction exist until you give an account for them first."

    Rather, the presuppositional apologist can use the existence of laws of logic in order to show a contradiction within the unbeliever's worldview, namely how he believes in universal, rational, prescriptive laws "within" or "inherent to" matter, a non-rational substance.
  22. chbrooking

    chbrooking Puritan Board Junior

    Hang on, I've been away and haven't really kept up. But reading through, I got lost at post 14. How did persuading a person that a God exists suddenly put them in the camp of "believer" and how did an argument that was supposedly sufficient quite apart from scripture now lead to them accepting that scripture is authoritative? The conversation went on to talk about contradiction and such, but I don't see how this major issue was missed. Suppose you persuade them that God exists, using the ontological argument. How did you move from God existing to God speaking, and speaking particularly in the Bible?
  23. ChristianTrader

    ChristianTrader Puritan Board Graduate

    An analogy of your position is this: "Someone claims that they own a car parked outside. You then respond that unless you tell me who made it and where they made it, then you cannot claim to own that car."

    It is basic to anyone who thinks.

  24. Philip

    Philip Puritan Board Graduate

    Let us pretend for a minute that my friend joe is now convinced that a good God exists. What I can do now is prove that goodness is not what he thought it was. Damnation, in fact, is a good and just thing.

    Fact is, we all start life by thinking autonomously. You cannot know God until you know yourself (insofar as that is possible without God).
  25. Whitefield

    Whitefield Puritan Board Junior

    Have you verified this with everyone who thinks? Or are you presupposing that everyone thinks this way?

    Your axiom seems to be "anyone who thinks rationally, thinks rationally on their own"; my
    axiom is "anyone who thinks rationally, thinks rationally because God thinks rationally."

    Re: your analogy about the car - if you try to title and register the car in Indiana you will need to prove those things.
    Last edited: Jun 13, 2009
  26. ChristianTrader

    ChristianTrader Puritan Board Graduate

    I am not an empiricist, so I do not see that I have any obligation to empirically verify everything.

    My sole claim is that there are rules and consequences for violating said rules. If the rules hold because God is rational or if they hold even if there is no God is not the present concern.

    There are definite things that you have to do to register the car, but the whether or not I can convince you that I own the care, is of no consequence of me owning the car or not.

  27. Whitefield

    Whitefield Puritan Board Junior

    Who is it that made these rules and consequences for their violation?

    It is if you are accused of having stole the car.
  28. Confessor

    Confessor Puritan Board Senior

    How can you possibly prove this objectively? You can try to give him principles (e.g. justice) that he might accept, but at no point is he rationally obliged to accept them. Why would an unbeliever desire justice anyway? How can justice be shown as important on a naturalistic basis? Nietzsche would certainly not care about such things.

    Even worse, at this rate, if an unbeliever has got you in a hole like this, he can keep asking questions until you prove on an autonomous basis that every single Bible verse is legitimate and "good." If the unbeliever is allowed to question the goodness of a Biblical doctrine and legitimately suspend belief until it is proven to be good, then he can legitimately suspend belief on every single thing in the Bible until it is proved on a separate basis. This is destructive of Biblical authority.

    Although we are prima facie justified believing in many things without having to directly recourse to God immediately (e.g. seven-year-olds can justifiably speak logically without having to give a transcendental account for knowledge), there still is a presupposition that we hold as self-evident that "flavors" every other belief in our noetic structure. And this presupposition can either be a belief that man has a prerogative to interpret reality, or God. The entire history of philosophy has generally believed it to be self-evident that man is responsible for constructing a philosophy himself, whereas Christians are to believe that God has already provided us with an authoritative revelation containing its own distinct philosophy. Christians understand that it is man's duty to submit to God's interpretation and not to construct one of our own.

    Now, one of these two beliefs, autonomy or theonomy, must be assumed at the outset. It cannot be proven that one has the prerogative to interpret reality at the outset on the basis of assuming that the other has it. There is no neutrality.

    As for your proposal that man must be autonomous, I reply that it is not necessary that he assumes man has the prerogative to interpret reality. I already conceded that there are several beliefs man is justified in holding (that he exists as a "self", sensory perception, reliability of memory, belief in laws of logic, etc., etc.), but it doesn't follow that man must assume an autonomous presupposition. Autonomy is not necessary in the least.
  29. Whitefield

    Whitefield Puritan Board Junior

    I don't think this is a fact; I think it is more an assumption.
  30. ChristianTrader

    ChristianTrader Puritan Board Graduate

    That is a legit question, to ask, once we have common ground that there are rules.

    If you want to use the analogy that way, my claim then is simply that I have a car. If you want to make the claim that I stole it, rightfully paid for it etc., that comes after my possession of the car. If I do not possess the car, then I cannot even be accused of stealing it.

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