Tuesday, July 13, 2010

What's a presupposition?

Dan Chapa seems to be confused about what Van Til meant by “presuppositions.” He makes oddball statements like “If God's existance [sic] can be demonstrated, then why presuppose it?” “Well given my observation that I have arms, my also presupposing that I have arms is minimally irrelevant, if not downright impossible.”

However, I don’t think there’s anything mysterious about Van Til’s usage. From my reading, Van Til uses “presuppositional” as a synonym for “transcendental” reasoning. Indeed, one synonym for presuppositional apologetics is transcendental theism.

So what does it mean to reason presuppositionally (i.e. transcendentally)? Well, as one scholar defines it:

Transcendental arguments are partly non-empirical, often anti-skeptical arguments focusing on necessary enabling conditions either of coherent experience or the possession or employment of some kind of knowledge or cognitive ability, where the opponent is not in a position to question the fact of this experience, knowledge, or cognitive ability, and where the revealed preconditions include what the opponent questions. Such arguments take as a premise some obvious fact about our mental life—such as some aspect of our knowledge, our experience, our beliefs, or our cognitive abilities—and add a claim that some other state of affairs is a necessary condition of the first one. Transcendental arguments most commonly have been deployed against a position denying the knowability of some extra-mental proposition, such as the existence of other minds or a material world. Thus these arguments characteristically center on a claim that, for some extra-mental proposition P, the indisputable truth of some general proposition Q about our mental life requires that P.

http://www.iep.utm.edu/trans-ar/

Van Till gives this type of argument a specifically Christian twist.

20 comments:

  1. "for some extra-mental proposition P, the indisputable truth of some general proposition Q about our mental life requires that P."

    So, for some extra-mental proposition "transcendent God exists," the indisputable truth of "we can only know him by revelation because we are non-transcendent creatures" require that "transcendent God to exist"

    Sounds right to me. Otherwise I'd be beginning my query with my own limited (and, in the case of Christian revelation of unredeemed anthropology, blinded) faculties.

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  3. Steve,

    Do you think that a VanTil-style transcendental argument would be more akin to a Strawsonian 'semantic entailment' theory of presupposition (as Don Collett argues in his chapter of Dr. Frame's festschrift) or Stalnaker's 'pragmatic presupposition' formulation? Or some 'third thing'?

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  4. I don't know that we can really extrapolate a trajectory from Van Til to the here and now. I think it's more useful to formulate or reformulate TAG using the most promising resources currently at our disposal.

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  5. Presuppositional considerations are relevant epistemologically. That we know anything begs the question of how we know it. So if we start there, it is empirically that we discover presuppositional options. We therefore weigh these options and from them use the one that best fits our desires - our visceral presuppositions. If we desire something to be true, we go with whatever presupposition results in that conclusion. The only exception is if our primary desire is to honestly know the Truth. This desire is given only by God and always results in the conclusion that God as revealed in Christian scriptures is the only true God.

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  6. Steve,
    I agree regarding any contemporary extrapolations from Van Til. What do you think are "the most promising resources currently at our disposal"?

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  7. Zao,

    Collett's use of Strawson's (Van Fraassen's, btoo, for that matter) notion of presupposition a good move. That notion recognizes that (well, for Van Tilians, at least) the existence of God is implied propositions by both p and ~p.

    However Collett's analysis fails to capture the *modal* character of VTAs, i.e., the *very possibility* of predication, human thought and intelligible experience.

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  8. Zao,

    Van Tilians need to actually develop a well-furnished alternative. They can do that by pursuing various leads in theistic modal metaphysics, as well as Plantinga's argument against evolutionary psychology, by combining the best elements of divine command theory and natural law theory, &c.

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  9. I'd add to what Steve said and recommend meta-level studies. I think presuppositionalism is best pursued as a meta-level project, so studies in meta-ethics, meta-philosophy, meta-logic, etc., should prove a fruitful line of inquiry. This focus will also help avoid a besetting sin presuppositionalists have seemed to fall into viz., making claims about what "the" Christian view on x is, while x is seriously underdetermined by the actual data of Scripture.

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  10. Interesting thoughts concerning Don Collett’s work. C.G. Weaver recently critiqued Collett’s formal TAG and concluded that it has no discernible logical form, its premises do not provide support for the conclusion, and it is not truth-preserving. Additionally the Strawsonian semantic view of the presupposition relation used in the “argument” entails either that bivalence is false, a many-valued logic is to be accepted, or that what is presupposed is always tautologically true even in cases where what is presupposed is obviously false. Mr. Weaver highlights the fact that Collett’s area is the Old Testament and that the view of presupposition he attempts to employ in order to develop a formal TAG has been almost unanimously rejected by philosophers since the 1970’s. (http://rfforum.websitetoolbox.com/file?id=1004963)

    Given Weaver's critique (which is by no means the first that has raised these difficulties and probably will not be the last) and given the concerns others have had about Collett’s formal TAG (e.g. It lacks the persuasive element of argumentation. – Frame) and given that it differs from how Greg Bahnsen formally stated TAG (which I have thus far not seen addressed by Bahnsen’s opponents) I am inclined to scrap the proposed formalization. Of course whenever one turns to currently popular notions in philosophy in order to establish the faith he or she can expect that they will fail to meet one's expectations of them. Fifty years from now philosophers will likely look back on the work of Alvin Plantinga and note that while he was undoubtedly a pivotal figure in the history of philosophy many of his ideas were mistaken. Given enough time even S5 might fall out of "relevant" philosophical literature as did its predecessors.

    This inevitable failure has characterized philosophy since its inception and seems to be what Van Til was warning us about all along.

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  11. Collett has his problems, but he made a step in the right direction. Looking in the direction of non-classical logics may indeed prove useful, like free logic, which doesn't depend on bivalence. Anyway, TAG does have a discernable form, but form takes the back seat to *content* with TAs.

    As far as Plantinga, don't many *currently* think he's mistaken on some matters?

    As far as pushing everything off into the skeptical future of "what if," well, "what if" Van Til turns out to be massively mistaken? You don't think so given what you can see and know now, and that's why we can confidently use S5 etc.

    (BTW, where did Bahnsen "formally state" TAG?

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  12. Thank you for the response.

    Stating TAG formally using free logic is an interesting idea that has no doubt occurred to some of Van Til’s modern day proponents. Unfortunately, Collett’s formalization is valid on neither classical nor non-classical logics. Additionally it endeavors to capture formally the essence of peculiar statements from Van Til and Bahnsen and neither of these men rejected bivalence. The problems with Collett’s formalization summarized above appear to be fatal and hence one is left wondering in what sense he has taken a step in the right direction.

    Certainly many even currently think that Plantinga is mistaken on some matters. He has nevertheless significantly influenced the climate of epistemological discussions. The suggestion is that there is 'an inconvenient truth' that will obsolete the paradigm. Given the history of philosophy this is not an unreasonable hypothetical though there may be difficulty taking it seriously in light of where things are philosophically.

    Van Til is not massively mistaken because he has captured a biblical epistemology (as difficult as it may be to state this epistemology in terms of the categories of current analytic philosophy). Of course insofar as Plantinga has done the same he is not mistaken either, but this is a concession to the proponent of Van Til. In any event Plantinga and S5 were only examples. Strawson’s understanding of presupposition may be a better example for the purposes of this discussion.

    Bahnsen states TAG in his lectures with Butler. Of course I am interested in the other discernible form of TAG you have in mind though I do agree with you that it "takes a backseat" to content.

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  13. Speaking for myself, I think "content" is the key issue. I think there's been way too much focus in Van Tilian circles on methodology, as if transcendental theism was an essentially technical issue of hitting on the right formulation.

    I don't see it that way. Rather, I see it in terms of developing a robust Christian ontology, epistemology, and axiology. I don't think there are any shortcuts to a well-furnished worldview. It's not so much "an argument," but a systematic alternative conceptual scheme.

    And when I say "Christian," that can, of course, include data from natural revelation as well as special revelation.

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  14. Anonymous,

    I'm not talking about Collett's formalization, I agree with many of the problems raised against it (I raised one myself). The step in the right direction was: "Collett's use of Strawson's (Van Fraassen's, too, for that matter) notion of presupposition was a good move. That notion recognizes that (well, for Van Tilians, at least) the existence of God is implied propositions by both p and ~p." This captures, for example, Van Til and Bahnsen's claim that no one can say a word *for* or *against* God without assuming his existence.

    And, yes, no one who states or captures a biblical truth is mistaken, but that's a rather uninteresting claim. The claim is whether Van Til or Plantinag *has* so captured said truth. You may think he has, just like many think current philosophical ideas are correct, but "the future" may render another verdict. The same criticisms that are given toward revision of philosophical theories also apply to revision of theological ones too. Both histories mirror themselves in important and substantive ways.

    I have listened to Bahnsen's lecture numerous times but am having trouble recalling where he "formally stated it." Is it the same as Butler's statement in The Standard Bearer? If so, Reiter recently criticized it. And of course, Choi criticizes it as well. So it wouldn't be true that "no one" has engaged Bahnsen's formula. If Bahnsen's is different, why did Butler stray? Butler seemed to indicate that Bahnsen's TAG had some problems that he did not adequately overcome.

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  15. Sure, but again, the Strawsonian semantic view of the presupposition relation entails either that bivalence is false, a many-valued logic is to be accepted, or that what is presupposed is always tautologically true even in cases where what is presupposed is obviously false, and these consequences are inconsistent with what Van Til and Bahnsen promoted. The view of presupposition Collett attempts to employ has been almost unanimously rejected by philosophers since the 1970’s (and iirc by Strawson himself). The reason that “the existence of God is implied propositions by both p and ~p… no one can say a word *for* or *against* God without assuming his existence” is – according to Bahnsen - that ~p would not be intelligible unless p were true; but this is quite different from what Collett is saying. The file name for the Bahnsen lecture is GB1824b. It is roughly 16 minutes long. I am having difficulty finding it now, but it is one of the last lectures in the series on TAG.

    Butler “roughly” states the form of a transcendental argument from philosophical literature on the topic of transcendental arguments. The link provided by Steve Hays follows this literature as well. Butler and Bahnsen argued extensively that TAG differs from other TAs. Butler’s formalization of TAs in general does not appear to differ from Bahnsen’s, however Bahnsen is much more thorough in his explanation of how the argument is formed and works. For example in this lecture, among other places, he explicitly denies that TAG is deductive, inductive, or analogy.

    Choi’s (alleged) reconstruction of Bahnsen’s argument is (correct me if I am wrong here, because I am working from memory):

    1) Logic
    2) If Non-Christianity then Non-Logic
    3) Therefore, Christianity

    …but this differs from what Butler has written, and it is certainly different from what Bahnsen stated. Certainly Choi goes on to build upon what is stated here, but note that neither Bahnsen nor Butler ever did.

    Reiter’s Type II formalization of TAG is (again from memory):

    1) Necessarily, if p then q
    2) p
    3) Therefore q

    If you have Reiter’s Type II formalization in mind then it does appear that I was mistaken when I stated that “thus far [I have] not seen [Bahnsen’s formal TAG] addressed by Bahnsen’s opponents” since I have read the Reiter article. However, I had a more explicit recognition of Bahnsen’s view of the argument in mind. One becomes suspicious when the entire context within which – in this case – Bahnsen states his argument is dropped out of an alleged critique of that argument. In any event I do not believe that TAG fails for the reasons provided by Reiter, and I look forward to a possible forthcoming response to that article due to some information I heard from a little bird.

    Meanwhile, the C.G. Weaver cited in my first comment has written some things in response to the comments from Steve Hays about “presupposition” beginning on pg. 4 http://rfforum.websitetoolbox.com/file?id=1005449

    Thank you for your thought-provoking responses. I have enjoyed the brief exchange!

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  16. And again, Van Fraassen and others have argued forcefully for free logic. There are intuitionists (who say that ~~p is not equivalet to p, etc) and dialetheists (there are some true contraditions), etc. Indeed, if we're lauding Bahnsen here, then his critique of "logic" should apply here too. When you get into meta logic, the field gets crazy and it's pretty unconvincing to say "but people disagree," especially when the one saying it says that everything philosophers have said almost "inevitably" goes out the window. Besides that, free logic does not say bivalence is false, it is simply not *committed* to it. And, some free logics are inclusive of bivalence (positive free logics), there are also bivalent semantics within free logic that allow truth value gaps. A friend of mine just went through an advanced logic summer session at Carnegie Melon with many famous logicians, according to him, free logic isn't as on the outs as you suggest here. Indeed, many think it a fruitful and prmising line of inquiry for many of the problems logicians are facing.

    The reason that “the existence of God is implied propositions by both p and ~p… no one can say a word *for* or *against* God without assuming his existence” is – according to Bahnsen - that ~p would not be intelligible unless p were true;

    'p' doesn't stand in for 'God,' it stands in for logic, science, morality, etc. It's hard to see what you could mean, given this qualification, by saying that "not-science" would not be *intelligible* unless *science* were true. No, the claim is meant to highlight the fact that TAs are *anti-skeptical*. So, you take what *the skeptic* asserts is the case, assume it for arguments sake, and show that it presupposes the transcendental for its intelligiblity.

    Secondly, Choi's presentation is not yours. His is the same as Reiter's, both following Stern.

    I also am not aendorsing Reiter's article, though he pushes the conversation forward. There may well be an article forthcoming in response to Reiter, in fact, I may have read one :-)

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  17. "Meanwhile, the C.G. Weaver cited in my first comment has written some things in response to the comments from Steve Hays about 'presupposition' beginning on pg. 4 http://rfforum.websitetoolbox.com/file?id=1005449"

    That url doesn't work for me.

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  18. Steve, I could email you a .doc of the content in the URL. Let me know. zaothanatoo@gmail.com

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  19. http://rfforum.websitetoolbox.com/file?id=1006638

    from William Lane Craig's Reasonable Faith website forums under "Evidentialism and Reformed Epistemology"

    C.G. Weaver comments on Manata's remarks.

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  20. "Thus these arguments characteristically center on a claim that, for some extra-mental proposition P, the indisputable truth of some general proposition Q about our mental life requires that P.

    Van Till gives this type of argument a specifically Christian twist."

    This might sound crass, but I don't see how a Van Tillian TAG argument can be defeated by an atheist.

    I listened to Bahnse-Stein tape once and Bahnsen destroyed Stein.

    It just seems that a Christian apologist could employ TAG, and blam! nuke the atheist's arguments to Kingdom come.

    The atheist might not come to believe in God, but he'll know that his position has just been left in shambles and that he's holding onto incoherency out of stubborness and spite.

    If an atheist has ever bested TAG, can someone point to it. And outline the strategy to neutralize TAG?

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