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You can read online James N. Anderson and Greg Welty’s paper, “The Lord of Non-Contradiction: An Argument for God from Logic,” Philosophia Christi 13:2 (2011): 321-338.

Here’s a summary:

In this paper we offer a new argument for the existence of God. We contend that the laws of logic are metaphysically dependent on the existence of God, understood as a necessarily existent, personal, spiritual being; thus anyone who grants that there are laws of logic should also accept that there is a God. We argue that if our most natural intuitions about them are correct, and if they’re to play the role in our intellectual activities that we take them to play, then the laws of logic are best construed as necessarily existent thoughts — more specifically, as divine thoughts about divine thoughts. We conclude by highlighting some implications for both theistic arguments and antitheistic arguments.

Next year Crossway will release a book from Vern Poythress that will include a similar line of argument; it’s entitled Logic: A God-Centered Approach to the Foundation of Western Thought.

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34 thoughts on “A New Argument for the Existence of God”

  1. Joe Torres says:

    Anderson and Welty have compiled a rather impressive argument for the ontological necessity of God. It is likewise worth noting that both authors are Van Tillians and that Van Til himself, as well as Greg Bahnsen, previously sketched out this type of argument.

    It’s great to see Anderson and Welty step up the argument with the type of rigor which they have. We need more like them.

    1. SLIMJIM says:

      Wow, are you with C&MA???

      1. Joe Torres says:

        Jim, no, I’m not with the C&MA, though I did attend and later taught at one of their colleges (Nyack College’s Manhattan Campus).

        Why the “wow”? :)

        1. SLIMJIM says:

          Oh I said wow, because I am going to attempt to be license with C&MA as a pastor…I’m surprised and encouraged to see that they have someone who is from RTS teaching for NYACK.

  2. Doug Perry says:

    Yes, I’m not seeing this argument as anything new. I’ve been hearing this approach from R.C. Sproul for years. However, I would push back on the above comment. Van Til and Bahnsen, while holding to an ontological argument, do not hold to the law of non-contradiction. This was one of Dr. Sproul’s strongest points against Bahnsen in their debate a few years back.

    1. Roger Ball says:

      I think you’re right. This is nothing new. Logic has always been a necessity for all contingency (how could it not?), and therefore an intrinsic necessity for the existence of anything, for the simple reason that it could have been something else.

    2. steve hays says:


      Van Tilians do hold to the law of noncontradiction. And what’s new is the rigor and detail of the argument.


      You’ve unwittingly illustrated the difference between an assertion and an argument. You just made an assertion about the necessity of logic, whereas Anderson and Welty present an argument.

      Moreover, it’s not just about the necessity of logic, but how that’s metaphysically grounded.

      1. Roger Ball says:

        Steve Hays,

        An assertion that demands “necessity” is an argument.

        1. steve hays says:

          You’re asserting necessity rather than arguing for necessity. Try to keep that basic distinction in view.

          And to say it “demands” necessity is precisely what you need to argue for. Try again.

        2. Walter Sobchak says:

          I think the claim that — Logic has always been a necessity for all contingency (how could it not?), and therefore an intrinsic necessity for the existence of anything, for the simple reason that it could have been something else.” — is an ethos. Kind of like saying nihilists believe in nothing.

          What if there were chaos and no laws of nature. This would seem to violate the above claim; yet, there would contingency without necessity. Perhaps a discussion of David Hume may be in order.

          Calmer than you are.

          1. Roger Ball says:

            Walter Sobchak

            You are describing a condition of “becoming” rather than “being.” Such a condition would be one of pure potentiality but actually nothing (no thing in particular). Chaos and no laws of nature could not possibly exist because they would posess no actual being or ground for doing so.

          2. Doug Perry says:

            Walter wrote, “What if there were chaos and no laws of nature.” The paper tried to address this question on page 4.

  3. I don’t see how arguing that rational thought would prove, in and of itself, anything? If someone believes that we evolved into such advanced creatures from non-life elements, I don’t think it’s much of a stretch of logic to also believe that evolution created logical thought as well.

    1. Doug Perry says:

      Naturalistic evolution that is driven by random processes without ultimate purpose or meaning has no need for or source from which to produce said “logic”.

    2. Roger Ball says:

      Redeem Christianity

      How would logical thought come into existence, whether through evolution or not, from a nonthinking environment? Evolution demands a program without a programmer; as RC Sproul would say, “this is a rabbit out of a hat, without the rabbit, or the hat, or the magician.”

    3. Ben says:

      Redeem Christianity

      The issue isn’t how humans came to think according to the rules of logic, but about the ontological status of the rules of logic.

    4. steve hays says:

      Redeem Christianity,

      Have you bothered to actually read their article?

  4. Thanks for plugging the paper, Justin.

    I’ve invited critical comments on the argument here.

    Some of your readers may appreciate the follow-up commentary I posted here, in which I connect the argument with some of Van Til’s distinctive claims.

  5. David S. says:

    This was an interesting read. It kind of reminded me of some versions of the transcendental argument. Though, it was different. I am not a professional philosopher by any means, but I think there are possible objections to this argument. At first glance, it seems contradictory to say that laws of logic are necessary, and then to say that they are thoughts…because thoughts are contingent upon a mind. Of course, they clarify that God is a necessary being and the laws of logic are necessary because they come from His mind. However, I’m sure most non-believers would just redirect the laws of logic as coming from the human mind, and not from God’s. Thanks for the article. I’m sure they have thought about these objections and have some reply to them.

  6. Mason says:

    Does anyone know if there is a preview for Poythress’ forthcoming book? Specifically, I’m wondering if he’ll teach logic, or simply talk about the role it’s played in western society.

  7. Paul says:

    Some of the above comments are funny. Take this one:

    Doug Perry:

    “Van Til and Bahnsen, while holding to an ontological argument, do not hold to the law of non-contradiction. This was one of Dr. Sproul’s strongest points against Bahnsen in their debate a few years back.”

    Van Til:

    “Christians should employ the law of contradiction, whether positively or negatively, as a means by which to systematize the facts of revelation.” (An Introduction to Systematic Theology, p. 11)

    Here’s another,

    Doug Perry:

    “Yes, I’m not seeing this argument as anything new.”


    “*This* argument” is not new? Perhaps you should tell the original author about this plagiarism. Of course, if all that is meant is that something like the *conclusion* of this argument has been around, well then it’s highly misleading to say that the argument *for* the conclusion is “nothing new.”


    “Roger Ball:

    “This is nothing new. Logic has always been a necessity for all contingency (how could it not?), and therefore an intrinsic necessity for the existence of anything, for the simple reason that it could have been something else.”


    Apart from the fact that it’s almost impossible to parse these two sentences, especially the latter, that’s not the argument; so not only is in an error to say the argument is not new, you haven’t even represented the argument.

    1. Doug Perry says:

      Paul, RC Sproul has used the premises and most of the points in this argument for a long time and that is what I stated above. It is possible for people to have similiar ideas without being guilty of plagiarism.
      As God’s Word tells us, there is nothing new under the sun.

      In fact, according to Romans 1, I would even go so far as to say that our best assertions and arguments are simply plagiarizing what our Creator has already given us thru general revelation. As such, our response ought to be to thank Him and Glorify Him. That’s what I’m going to do right now. Blessings.

  8. Paul says:

    Doug, I just quoted Van Til affirming, not denying, the law of non-contradiction. Same with Bahnsen, e.g., his debate with Stein, his book *Van Til’s Apologetic*, etc. So, you were wrong to say what you did, and so was Sproul, if he even said it (it’s been a while since I listened to that debate; I thought he was more concerned with what he took to be a confusion between the order of being and knowing),

    Second, “ideas” aren’t “arguments.” As I said, I know people have come to the same conclusion, and even perhaps had rough, in-the-ballpark, inchoate ideas, yet it’s a stretch to get from there to “same argument”—unless, of course, one either doesn’t know what an argument is or is using that term in a very broad or even idiosyncratic sense.

    In any case, I guess I have no response for apparently the exegetical intent of Solomon’s saying is that James and Greg’s argument is “not new.” What a prophet he was! I stand corrected.

    I also don’t think Paul’s saying what you think, especially given the rhetorical flourishes you’ve put on it. But we’re getting into areas I don’t want to discuss with (most) Reformed Christians, I was just pointing out the mistaken claim about VT and Bahnsen’s alleged rejection of the LNC, as well as the mistake in claiming the *argument* has been around, with apologies to Solomon, of course.

    1. SLIMJIM says:

      Will you be coming back to the blogging world? I’ve always been blessed by your work.

    2. Doug Perry says:

      Paul, I suggest you become more famililar with the work of Dr. Sproul. Most of your problems will be addressed if you spend some time with his work (written and recorded) on Classical Apologetics.

      Secondly, I understand your concern about my original statement regarding VanTil and Bahnsen with regard to the law of non-contradiction. I clearly mispoke by saying that they don’t “hold to” the view.

      HOWEVER — when VanTil and Bahnsen take the approach that you quoted: “Christians should employ the law of contradiction, whether positively or negatively, as a means by which to systematize the facts of revelation.” (An Introduction to Systematic Theology, p. 11), they are not arguing that the law of non-contradiction is a valid premise for arguing for God’s existence.
      That is the point that I’m making in that regard.
      Rather than referencing Bahnsen vs. Stein, I’d prefer that you consider Sproul vs. Bahnsen and some other critiques of how Bahnsen employs the rules of logic, such as non-contradiction and the excluded middle. I think you’ll see a profound difference between their approaches, and you’ll also be able to confirm that Sproul has had the same argument that JT is referring to here for a long time. AND Sproul has no illusions that his argument is new to him, as he traces it to church fathers and other apologists in the Classical style.
      Presuppositionalists are awakening to classical emphases and think they’re finding something new. (as far as Romans 1 goes, I commend Calvin’s Institutes to you for the best treatment.)

  9. Derek DeVries says:

    The laws of logic are rules. And these rules can, but need not, be stated on proposition form according to which they would be truth-apt. The laws of logic, in themselves, are not the kind of thing that has any truth value; only propositional statements expressed in the some language is capable of having any truth-value. Thus, saying that the laws of logic are truths is false, or sloppy at best. Therefore, the conclusion that the laws of logic are metaphysically dependent on the existence of God does not follow necessarily. The argument is deductively unsound.

    1. Derek,

      Your criticism is dealt with (implicitly) on page 4 of the paper. Just substitute “truths about the laws of logic” for “laws of logic” and the argument goes through just as well. If there’s at least one necessary truth, that’s enough for the argument. Do you want to deny that there are any necessary truths?

      1. Derek DeVries says:

        The discussion on propositions in page 4 is found wanting. Here’s why: The English statement “Snow is white” and the German statement “Der Schnee ist weiß” are two different sentences about the same proposition. This is pretty elementary. If indeed snow is white, then the fact that snow is white is a proposition that merely obtains, without its needing to be expressed in any language whatsoever in order for it to obtain. Now in that case, the fact that snow is white — the proposition — is the *truthmaker*. It is a truthmaker for the possible truth of the sentence “Snow is white” or “Der Schnee ist weiß”, which are truthbearers; they are truth-apt sentences, which may have a truth-value assigned to them. This is a fairly non-controversial, standard way of parsing out the distinction between propositions and sentences. I think it is *far more* controversial to claim that propositions (1) are truthbearers, since this unnecessarily multiplies the amount of truthbearers in question (beside the truth-value for proposition p, you also have a truth-value for sentence “p”), and that propositions (2) have a “nature” to them, namely that it is their “nature” to bear truth-values. This metaphysical view of propositions must be defended: that propositions have a “nature” to them is not self-evident. This “nature” of propositions sounds like a rather spooky property, if it is. Or is it that, more nominally, “nature” merely describes class-membership? At any rate, page 4 could have been more precise about these issues. By the time it is said in page 4 that the laws of logic are propositions, we already have prima facie reasons to doubt that. Without a clearer account of propositions, it becomes hard to see in what sense *rules* such as the laws of logic are propositions. A rule, properly speaking, is the kind of thing that one follows. It is unlike a proposition, which is the kind of thing that one represents, say, by the utterance of a linguistic expression. A proposition is not a rule for the reason that one does not follow a proposition. A proposition is a proposition. A rule is a rule. To say that “the laws of logic are propositions” (page 4) is to problematically conflate rules with propositions.

        1. Walter Sobchak says:

          So propositions are true or false. The sentence ‘Snow is white.’ expresses the proposition SNOW IS WHITE and it is the proposition itself which is true or false. Sentences do not possess truth-values. The meanings of sentences are the propositions that they express. I don’t know whose view that your presenting but I don’t know of anyone who claims that sentences have truth-values while claiming that propositions have truth-values. Perhaps your confusing sentences with the various types of propositions that they may express. Some claim (Robert Stalnaker being the most well known) that sentences express propositions and define propositions as the set of all possible worlds in which the proposition is true. Others claim (Jeffrey King, Scott Soames) that sentences express a more fine-tuned proposition which is an n-ary relation between an object(s) and property(s).

          I think perhaps your confusing the work of Greg Welty with Greg Schmelty. It has happened before. Similar to Greg Welty, Greg Schmelty began his undergraduate work in philosophy at UCLA however Schmelty had to leave the program shortly after beginning due to his arguments with David Kaplan and Keith Donnellan. Schmelty argued with Kaplan that demonstratives had a Fregean sense which was semantic in nature and indirectly picked out the referent of a demonstrative. Schmelty argued with Donnellan that descriptions which were attributive had Fregean senses that picked out the referent which was a semantic mechanism.

        2. Derek,

          I’ve posted my reply here.

          The short version:

          You say I’ve conflated rules with propositions; I say you’ve conflated facts with propositions. The literature seems to side with me, and in any event the point has no relevance to the cogency of the argument presented in our paper.

  10. Alan Yates says:

    Logic is a necessary result of things existing. The nature of what exists determines what will be logical. Logic itself isn’t anything but the relationship of what is created by God. Faith is the evidence of things not seen.

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Justin Taylor, PhD

Justin Taylor is executive vice president of book publishing and book publisher for Crossway and blogs at Between Two Worlds. You can follow him on Twitter.

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