Dialogue
Should Natural Science
Include Revealed Truth?
A Response To Plantinga
William Hasker
Department of Philosophy
Huntington College
Huntington, IN 46750
From Perspectives on Science and Christian Faith 45 (March 1993): 57-59.
I am grateful to Alvin Plantinga for his reply to my discussion of his debate with McMullin and Van Till,1 and to the Editor for giving me the opportunity to respond. I shall be discussing two main topics: the need for Plantinga to provide an alternative to the theory of common ancestry (TCA), and his proposal for "theistic science."
Both Ernan McMullin and I have urged that if Plantinga is going to reject evolution he needs to present his own view about how the variety of living things on the earth, past and present, came about. Plantinga disagrees, and rightly sees this as a major point at issue between us. Unfortunately, however, he devotes most of his space to refuting a view which I have never endorsed and do not hold. I do not believe that, in general, "if you reject a theory or explanation as unlikely on the evidence, you have to be prepared to propose some other theory in its place," with the rider that the replacement theory must be "equal in content" with the theory it replaces. Certainly I may think it improbable, less likely than not, that a given horse will win the Kentucky Derby, without being prepared to say which horse will be the winner.
My own reasoning for saying Plantinga needs to present an alternative is much more specific. In the interest of conciseness, I present it here in the form of an argument with numbered steps:
1. The modern natural sciences over the past several centuries have proved to be by far the best method we have of learning the truth about the structure, processes, and history of the natural world. (They have been incomparably more successful than the speculations of creationists.)
2. Therefore, one who wishes to learn about these things is well advised to study and carry out research in these sciences.
3. Once a theory has enjoyed some success and has established itself in some branch of the natural sciences, the normal and appropriate scientific procedure is to continue to accept that theory until it can be replaced by a superior alternative.
4. Therefore, one who wishes to gain increased knowledge concerning the natural world is well advised to follow the procedure outlined in step 3.
Presumably Plantinga would not agree with this, but it is not clear to me just which step(s) he would object to. Perhaps he would agree with (3) if properly qualified;2 at least, he has so far shown little disposition to contest it. Is it the case, then, that he supposes he has access to some other method of study (perhaps the method exhibited in his two articles) which is better, more likely to reach the truth, than the methods of the natural sciences as generally practiced? I don't know the answer to this; perhaps Plantinga will explain sometime.
In any case, I do have another reason for insisting that Plantinga needs to specify an alternative, and this reason is drawn from his own procedure. In several places Plantinga makes assertions to the effect that some piece of putative evidence for evolution is "reasonably probable on the hypothesis of special creation, hence not much by way of evidence against it, hence not much by way of evidence for evolution" (p. 23, and see similar remarks on pp. 24, 104, 105, and 107-8). My question is, "Which hypothesis of special creation is referred to here"? Plantinga replies that "the hypothesis of special creation I had in mind was just the hypothesis that
SC: God created at least some forms of life specially, in a way that did not involve common descent."
Now, the particular piece of evidence referred to on p. 23 is simply the "similarity in biochemistry of all life." And with regard to that particular evidence, I will admit that SC is specific enough to enable us to see that Plantinga's claim is true; it is reasonably probable that God, in specially creating a variety of living creatures, would have endowed them with similar chemistries.
But Plantinga makes similar assertions about other types of evidence, and to evaluate these assertions we do need a more specific creationist hypothesis. He says, for instance, that "The fossil record fits versions of special creation considerably better than it fits TCA" (p. 104), and also that "the typological structure of the molecular evidence fits very well with various typological views as to how God might have created some forms of life specially" (pp. 107-08). Now "the fossil record" and "the typological structure of the molecular evidence" represent very broad categories of evidence. And with respect to those categories of evidence, I submit we cannot evaluate Plantinga's claim without knowing more specifically which creationist hypothesis he has in mind. The crucial question, of course, is which of the alleged evolutionary transitions does he accept and which does he reject? If we are considering the evidence of the hominid fossils, for instance, or the remarkable genetic similarities between humans and chimpanzees, then it makes a great deal of difference whether the hypothesis in question accepts the ape-human transition as valid or rejects it. So as I pointed out before, the question that cries out for an answer is, at what taxonomic level are the acts of special creation supposed to have occurred?3 Plantinga's response, I take it, is that he doesn't know the answer and doesn't need to know. My view is quite different; I believe that without an answer to this question Plantinga's assertion that some special creationist theory is more probable than TCA represents a pious hope but not a proposition that either we or he can seriously attempt to evaluate.
What shall we say about "theistic science," Plantinga's proposal for a special, distinctively Christian discipline of natural science which incorporates "what we know by faith, by way of revelation, as well as what we know in other ways" (p. 30)? I think it needs to be emphasized that our disagreements about theistic science are less extensive than they might appear. To begin with, I wish to limit my comments here to the natural sciences; the sciences of human behavior raise different issues which require separate treatment. My disagreement, furthermore, is specifically with the proposal for a natural science which includes content derived from faith and revelation. But I would strongly encourage Christians in the sciences to reflect critically about their scientific work in the light of their Christian faith, and to endeavor to arrive at a comprehensive world view, integrating their scientific understandings with their faith perspective (see my comments on p. 159). Now this task, also, would be included by Plantinga under the heading of "theistic science," and with regard to that part of his program we have no disagreement whatever. I mean to focus, then, on the idea that natural science should include content derived from revelation. About this, three points need to be made.
To begin with, if we understand "theistic science" in this restricted sense, Plantinga's claims about the dangers of rejecting it are unwarranted. He says such rejection carries with it the dangers of "failing to discern the patterns and currents of spiritual and intellectual allegiances of contemporary culture, intellectual compartmentalization, failing to lead all of life captive to Christ, [and] being conformed to this world." I agree that, were Christians in the sciences simply to ignore issues of integration between faith and science, the dangers Plantinga cites would threaten. But I do not think these dangers are especially pressing if these scientists follow the suggestion to intensively pursue issues of faith and science, but without incorporating content from revelation into their scientific theories.
My second point is this: When we are working with the restricted conception of theistic science, it becomes apparent that TCA is not merely a handy illustration, but is rather the point on which the whole debate hinges. The reason for this is that the question of evolution vs. special creation is really the only substantial point concerning which it is still claimed that revelation provides knowledge which natural science must incorporate. It wasn't always this way, of course. We all know the sad story of Galileo and the Church; since then, astronomy has generally been left to the astronomers.4 There is an equally impressive, though less well known, story of the retreat and eventual disappearance of "biblical geology," as one attempt after another to harmonize earth history with data derived from Genesis has gone awry.5 So if the claim that the Bible teaches special creation has to be given up, there won't be any biblical data left to incorporate into natural science.
My third point is simply to point out that Plantinga has made no case for saying that Scripture does teach special creation. To be sure, he thinks it likely that God "intends to teach us that human beings were created in a special way and by an act of special creation" (p. 82) (though he doesn't believe that God intends to teach us this!6 ). But I pointed out in my discussion (and Plantinga doesn't contest this) that he fails entirely to give us any reasons to suppose that his favored interpretation (on this and related matters) is correct (see pp. 153-54). So on the crucial point (with respect to the narrow sense of "theistic science") he gives us nothing to go on.
But things are even worse than this. In my discussion I said that Plantinga should find "devastating" the view of James Barr according to which the author(s) of Genesis intended to teach a literal six day creation, a young age for the earth and mankind, and a universal flood. In reply Plantinga reminds us of his view (which he shares with Calvin and Aquinas) that God is the ultimate author of Scripture, and that what matters is what he (and not the human authors) intends to teach us through it. Quite so, and I, also, am happy to say that what ultimately matters is what God is teaching us in the Bible.7 But to say this underscores the need for some systematic account of how it is that we distinguish what God is teaching us from the other things the text apparently says which God does not intend to teach us. In short, we need a hermeneutic of Scripture. But here's the rub: I believe (though the point can't be argued here in detail) that the case in the biblical text for saying that God is teaching us that the earth is young, that it was created in six literal days, and that it was covered by a universal flood, is very much on a par with the case for saying he is teaching us about the special creation of human beings. If that is so, then it is extremely likely that any sensible hermeneutic which removes young-earth theory from the scope of "what God is teaching us in the Bible" will do the same for special creationism. In order to defend Plantinga's view, on the other hand, one would have to be able to distinguish, in some principled way, between the special creationism which God supposedly is teaching us, and the young-earth theory which he can't be teaching us, since we know on independent grounds that it is false. It's conceivable that this can be done, but my present attitude towards such a project is one of deep skepticism.
I conclude, then, that there is no credible case for the view that Christians should attempt to construct a "theistic natural science" which includes content derived from revelation. But there are other aspects of Plantinga's proposal for "theistic science" which are admirable and deserve to be pursued vigorously.
NOTES
1 See Alvin Plantinga, "When Faith and Reason Clash: Evolution and the Bible," pp. 8-32; Howard Van Till, "When Faith and Reason Cooperate," pp. 33-45; Pattle Pun, "Response to Professor Plantinga," pp. 46-54; Ernan McMullin, "Plantinga's Defense of Special Creation," pp. 55-79; and Alvin Plantinga, "Evolution, Neutrality, and Antecedent Probability: A Reply to McMullin and Van Till," pp. 80-109; all in Christian Scholar's Review XXI:1 (September 1991); also my article, "Evolution and Alvin Plantinga," in Perspectives in Science and Christian Faith Vol. 44 No. 3, September 1992, pp. 150-162 and Plantinga's reply, "On Rejecting the Theory of Common Ancestry: A Reply to Hasker," Perspectives on Science and Christian Faith Vol. 44 No. 4, December 1992, pp. 258-263. Page references in the text are to these articles.
2 Plantinga quite properly points out (fn. 4) that a theory inconsistent with known data cannot be accepted as completely true; such a theory may, however, be accepted as substantially true, or approximately true, or perhaps (as Plantinga says) as being "in the neighborhood of truth." And what is required of the replacement theory is that it be more likely to be true, more "truth- like," than the theory it replaces" as shown by its better satisfying the various desiderata standardly applied in judging scientific theories.
3 Thus, my claim is not that the replacement hypothesis must be "equal in content" with the hypothesis it replaces, but that it must be specific enough to enable us to evaluate the evidence which is alleged in favor of the original hypothesis.
4 There remains, to be sure, the question of whether or not the universe has a temporal beginning. But even if we think Christian faith requires an affirmative answer to this question, it surely is not essential that this answer should be part of the science of astronomy. If astronomy were to find no evidence for a temporal beginning we could simply revert to the position of Thomas Aquinas, who held that the world does have a temporal origin but that this fact is undiscoverable by natural reason (and thus is not a part of natural science) and must be accepted by faith.
5 This history is well documented by Davis Young in Portraits of Creation, as well as in his earlier book, Christianity and the Age of the Earth (Grand Rapids: Zondervan, 1982).
6 And herein lies a tale. Misunderstandings have arisen because of the fact that Plantinga and I use the word "believe" somewhat differently (see fn. 5 of his response). Plantinga will say that he believes a proposition only when he can give unqualified assent to that proposition; if on the other hand he considers it a genuine possibility that the view he favors may be mistaken, he will not say that he believes the proposition in question but only that he thinks the proposition likely, or probable. I, on the other hand, use "believe" somewhat more liberally. So I would say of myself that I believe that TCA is true, but that it's possible that I am mistaken and that some version of special creation is true instead. Plantinga, on the other hand, would describe this situation by saying that I think TCA is probable but I don't (in his sense) believe it. (I think my way of using "believe" would be accepted by most users of standard English, but I'm not sure about that. Which is to say: I believe my usage is the normal one, but I could be wrong!)
7 As regards Aquinas and Calvin, however, I think Plantinga is glossing over an important difference between his position and theirs. If Barr's view concerning the intention of the authors of Genesis is correct, then the text of the Bible says, and was intended to say, that the earth was created in six literal days a few thousand years ago and was covered by a universal flood in historical times. If so, then Plantinga would be forced to say in spite of this that God never intended us to believe any of this and in fact it is all definitely false. I submit that both Aquinas and Calvin would have found this to be utterly scandalous.