Has Plantinga “buried” Mackie’s logical argument from evil?

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Transcript of Has Plantinga “buried” Mackie’s logical argument from evil?

  • Int J Philos Relig (2014) 75:189196DOI 10.1007/s11153-014-9448-3

    ARTICLE

    Has Plantinga buried Mackies logical argumentfrom evil?

    Anders Kraal

    Received: 14 January 2014 / Accepted: 21 February 2014 / Published online: 4 March 2014 Springer Science+Business Media Dordrecht 2014

    Abstract In seeking to undermine Mackies logical argument from evil, Plantingaassumes that Mackies argument regards it as a necessary truth that a wholly goodGod would eliminate all evil that he could eliminate. I argue that this is an interpre-tative mistake, and that Mackie is merely assuming that the theist believes that Godsgoodness entails that God would eliminate all evil that he could eliminate. Oncethe difference between these two assumptions, and the implausibility of Plantingasassumption, are brought out, Plantingas celebrated critique of Mackies argument canbe seen to be far less compelling than is often assumed to be the case.

    Keywords John Mackie Alvin Plantinga Logical argument from evil Problem of evil

    In Evil and Omnipotence (1955) Mackie famously argues that the three beliefs

    (1) God is infinitely powerful,(2) God is wholly good, and(3) evil exists,

    are inconsistent, and in so arguing he appeals to the further premises

    (4) there are no limits to what an omnipotent thing can do, and(5) a wholly good thing always eliminates evil as far as he can.

    In view of the alleged inconsistency, Mackie judges that theists (or at any rate theistswho hold the relevant beliefs) are positively irrational.1

    1 Mackie (1955, pp. 200201). In subsequent writings Mackie identifies the relevant sorts of theists astraditional theists; see e.g. Mackie (1962, p. 153; 1982, p. 150).

    A. Kraal (B)University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canadae-mail: [email protected]

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    In The Nature of Necessity (1974a) and God, Freedom and Evil (1974b) Plantingaargues, also famously, that Mackies argument isnt sound.2 So influential has Planti-ngas reasoning been that it is today widely assumed, among analytic philosophers ofreligion, that Mackies argument has been buried.3

    Plantingas argument against Mackie rests on a largely unexamined interpretationof Mackie, however, and only holds if this interpretation is exegetically sound. Thosewho hold that Plantinga has buriedMackies argument assume, in effect, that Planti-ngas interpretation is exegetically sound. Nonetheless, I shall venture to argue that acompelling case can be made for regarding Plantingas interpretation as exegeticallyunsound, and in such a way as to render his argument against Mackie unsuccessful.In what follows I seek to substantiate this claim.

    Plantingas assumption that Mackie proposes (5) as a necessary truth

    Plantingas critique of Mackie comprises two main parts. The most well-known partis the Free Will Defense, which is a way of arguing that [] (1) and (2) are in factconsistent [with (3)].4 In arguing this conclusion, the Free Will Defense seeks toidentify a proposition that is (i) possible, (ii) consistent with (1) and (2), and (iii) suchthat in conjunction with (1) and (2) it entails (3).5 The proposition Plantinga suggestscentres on the claim that Every possible person suffers from transworld depravity,that is, that every possible person is such that there is some morally significant actionwith respect to which they would go wrong and hence would introduce some evil intothe world.6

    The Free Will Defense builds on what Plantinga calls his first project, however,which consists in explor[ing] the ways in which the atheologian might argue that (1)and (2) are incompatible, and to point out that this is enormously more difficult thanthe atheologians seem[] to suppose.7 More specifically, the first project consists inarguing, in opposition to what Plantinga takes to be Mackies view, that (4) and (5)arent necessary truths, and so cant be properly used to derive a contradiction from(1)(3). This first project has received relatively little attention in the literature, whichinstead has been dominated by discussions of the FreeWill Defense. It is worth noting,though, that the success of Plantingas Free Will Defense depends on the success ofthe first project. It is in connection with this first project, I shall argue, that we find acrucial interpretative mistake on the part of Plantinga.

    2 See Plantinga (1967, pp. 115155; 1974b, pp. 1255; 1974a, pp. 164190).3 See e.g. Dougherty (2011, p. 560).4 Plantinga (1985, p. 41).5 See Plantinga (1974b, p. 26).6 Plantinga (1974a, pp. 184189; 1974b, pp. 4954). Note that I say that Plantingas additional propositioncentres on the claim that Every possible person suffers from transworld depravity, which is not to saythat this claim is identical to the relevant proposition. The relevant proposition is in fact a conjunctiveproposition consisting of this claim in conjunction with the further proposition that God created a worldcontaining moral good; see Plantinga (1974a, p. 189; 1974b, p. 54).7 Plantinga (1985, pp. 4041).

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    In seeking to show that the conjunction of (4) and (5) isnt a necessary truth,Plantinga grants that (4) is necessarily true (with the minor qualification that thelimits spoken of in (4) are nonlogical limits),8 and in what follows I shall allowthat Plantinga is justified in this. With regard to (5) Plantinga is more critical, however.His objection, in brief, is that a good person would not be obliged to eliminate a givenevil if they could do so only by eliminating a good that outweighed it.9 In line withthis it is suggested that if a wholly good being could eliminate all evil in the worldonly by eliminating outweighing goods, then it is far from clear that a wholly goodbeing would eliminate all evil in the worldin which case (5) wouldnt be a necessarytruth.10

    Suppose that Plantinga is right in this, and that he accordingly has succeeded inshowing that (5) isnt a necessary truth. Does it follow that Mackie is wrong in con-tending that (5) can be used to show that (1)(3) is contradictory? Only if we supposethat Mackie is proposing (5) as a necessary truth.

    Interestingly, in God and Other Minds Plantinga recognizes that (5) could be putto effective use in Mackies argument even if it falls short of being a necessary truth,provided it is either essential to theism or a logical consequence of claims essentialto theism.11 But he doesnt entertain seriously the possibility that these latter thingsare what Mackie had in mind, regarding it instead as more or less obvious that Mackieproposes (5) as a necessary truth in its own right.

    Why does Plantinga take Mackie to be proposing (5) as a necessary truth? Becauseif these claims arent regarded as essential to theism or as logical consequences ofclaims essential to theism, the claim can only be used to generate a contradictionwith (3) if it is a necessary truth in its own right. To better understand Plantingasreasoning on this point we do well to attend to a few preliminary definitions. Anexplicit contradiction, says Plantinga, is a conjunctive proposition, one conjunct ofwhich is the denial or negation of the other conjunct.12 In line with this a set ofpropositions is said to be explicitly contradictory if one of the members [of the set]is the denial or negation of another member.13 A set of propositions, moreover, issaid to be formally contradictory if an explicit contradiction can be deduced [fromit] by the laws of logic.14 With the help of these definitions Plantinga introduces thenotion of implicit contradiction, which he defines as follows: a set S of propositionsis implicitly contradictory if there is a necessary proposition p such that the resultof adding p to S is a formally contradictory set.15 We can now see why Plantingatakes Mackie to propose (5) as a necessary truth: if (5) were only a contingent truth,there would be some possible world in which it would be consistent with (3), in which

    8 Plantinga (1974b, p. 17).9 Plantinga (1974b, p. 20).10 Plantinga (1974b, pp. 2224; cf. p. 54).11 Plantinga (1967, p. 117).12 Plantinga (1974b, p. 12).13 Plantinga (1974b, p. 13).14 Plantinga (1974b, p. 14).15 Plantinga (1974b, p. 16).

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    case it wouldnt contradict (3), since it contradicts (3) only if it entails (3) in everypossible world.

    Plantingas idea that Mackie is proposing (5) as a necessary truth is of course con-nected to his more basic idea that Mackies contention is that (1)(3) is implicitlycontradictory (in the above defined sense). For (1)(3) to be implicitly contradictoryit is required that there is some further proposition which is both necessary and suchthat in conjunction with (1)(3) it yields a formal contradiction. This further propo-sition, Plantinga thinks, is in Mackies argument the conjunction of (4) and (5). SaysPlantinga:

    [W]hen Mackie says that set A is contradictory, we may properly take him, Ithink, as holding that it is implicitly contradictory in the explained sense. []What he means, I think, is that to get a formally contradictory set we must addsome propositions to set A (i.e. [4] and [5]); and if we aim to show that set A isimplicitly contradictory, these propositions must be necessary truthsquasi-logical rules, as Mackie calls them.16

    Inwhat follows I argue that Plantinga ismistaken in assuming thatMackie is proposing(5) as a necessary truth.

    Does Mackie propose (5) as a necessary truth?

    Mackie formulates his basic contention as the claim that the theistic claims (1) and(2) are inconsistent with (3), and that religious beliefs are by consequence positivelyirrational on account of their contradictoriness.17

    NowMackies contention that (1) and (2) are inconsistent with (3) could