by Raymond J. VanArragon

In the last thirty years or so, Christians have made deep inroads in philosophy departments at universities in the United States and elsewhere.  The Society of Christian Philosophers, an organization started in 1981, now hosts important conferences every year, produces a highly respected journal, and boasts over 1000 members.  Many up-and-coming Christian scholars have found their calling in philosophy defending the rationality of religious belief, offering arguments against anti-Christian worldviews, exploring issues in philosophical theology, and drawing out the implications of Christian belief for their philosophical views.

here are several superb philosophers who deserve credit for this resurgence in Christian philosophy.  But arguably the person most important to the movement has been Alvin Plantinga, currently the John A. O’Brien Professor of Philosophy at the University of Notre Dame.  His role has been widely recognized.  Already in 1980, Time magazine, in a story noting the increasing prominence of Christians in philosophy, labeled Plantinga “the leading Protestant philosopher of God.”1 More recently, Quentin Smith, editor of the journal Philo, credits (or maybe blames) Plantinga for helping to unravel the “secularization of mainstream academia.”2  In my own view, it is no exaggeration to call Plantinga a hero of the faith.  Christians can truly benefit from learning more about his contributions to Christian scholarship and his defense of the faith.



Alvin Plantinga was born in 1932 in Ann Arbor, Michigan, and spent much of his early life in North Dakota.  A descendent of Dutch immigrants, he grew up in the Christian Reformed Church, the denomination that founded Calvin College.  When he was seventeen, his family moved to Grand Rapids where his father began teaching psychology at Calvin.  At first Plantinga did not want to go to school there himself, so when to his surprise and delight he won ‘a nice fat scholarship’ from Harvard University, he headed off to Cambridge instead.  His life took a turn, however, when on a break from Harvard during his freshman year he happened to attend a class at Calvin taught by legendary philosophy professor William Harry Jellema.  Plantinga was so impressed that he decided right then to transfer.  This turned out to be a decision of monumental importance for him, since studying at Calvin did much to preserve his Christian faith and shape his approach to issues of reason and religious belief.

After he graduated from Calvin, Plantinga moved on to earn a Master’s degree from the University of Michigan and a PhD from Yale.  (During this time he also married Kathleen DeBoer, whom he had met at Calvin.)  He reports that he did not particularly enjoy his time at either place, though it is clear that his talent and potential were already apparent to those around him.  One indication of this is that while at Yale, he did not have to go through the usual step of asking a professor to serve as his dissertation director; instead, one of his professors asked him!4  Upon completion of his PhD, he was lured to Wayne State University in Detroit where George Nakhnikian, the energetic department chair, had managed to round up one of the most dynamic collections of young philosophers in the country.5  Plantinga’s colleagues were not themselves Christian, but he learned a great deal from them about how to do philosophy.  It was there that he developed the style of precision and care in argumentation that, together with his sharp wit, became his trademark.

After several years at Wayne, Plantinga accepted an invitation in 1963 to replace the retiring Harry Jellema at Calvin.  Plantinga spent the next nineteen years there, and during that time he published some of his most important books.  In 1967 came God and Other Minds, followed in 1974 by The Nature of Necessity.  In 1982 he moved on to the University of Notre Dame, where he has been ever since.  His opening address at Notre Dame, “Advice to Christian Philosophers,” challenged Christians to take more seriously their religious commitments and responsibility to the Christian community in their academic work.  In 1983 he published his seminal essay, “Reason and Belief in God,” which was part of a famous collection titled Faith and Rationality.  More recently he has authored the Warrant trilogy, starting with Warrant:  The Current Debate and Warrant and Proper Function in 1993, and concluding with Warranted Christian Belief in 2000.



Plantinga was known to be a promising philosopher while still a graduate student and later as a professor at Wayne State.  But his fame in the philosophical world spread with his development of the free will defense, versions of which appear in God and Other Minds and The Nature of Necessity.

Here’s the set-up.  J. L. Mackie, a prominent atheist from Oxford University, had in 1955 published an article called “Evil and Omnipotence,” in which he argued that it was in the strongest sense impossible for God and evil to coexist.  He claimed, in short, that if God, an omnipotent and perfectly good being, existed then there could be no evil.  After all, a perfectly good being would eliminate all the evil it could, and an omnipotent being would be able to eliminate all evil.  The fact that there is evil, then, entails that God does not exist.  This argument was for years quite widely accepted in philosophical circles.  And it was troubling for Christians, since if God’s existence was straightforwardly incompatible with the existence of evil, then theism could only be accepted on pain of blatant irrationality.

The aim of Plantinga’s free will defense was modest:  he simply wanted to refute Mackie’s contention that it was impossible for God and evil to coexist.  To do this, he hoped to describe a possible situation in which God and evil co-exist.  If such a situation is in fact possible (if it could possibly occur), then it is possible for God and evil to co-exist; but then, obviously, Mackie’s contention that that’s impossible is mistaken and he has not successfully shown belief in God to be irrational.

We can understand the possible situation Plantinga came up with by first considering two assumptions.  First, there all sorts of possible worlds—all sorts of ways that things could be.  (In the actual world, George W. Bush is re-elected president in 2004; but things could have been different, meaning that, for example, in many possible worlds he loses that election and in many possible worlds he doesn’t even run.)  Some of these worlds may seem better than the actual world (it seems that things could be better than they are), while others seem considerably worse.  If God exists, then God would only actualize a really fine world, the very best world he could.  It would be beneath God, inconsistent with his goodness, to create a really despicable or even a mediocre world.  The second assumption is that morally significant freedom is a valuable thing, so that a world containing creatures with the freedom to choose between right and wrong is better than a world containing only complex automatons, all else being equal.

Now in light of those assumptions, Mackie’s argument is essentially this:  if God exists, then he must create the best possible world, namely, a world with freedom but no evil.  But how might God create a world like that?  He couldn’t just create free creatures and then always compel them to freely do what’s right; because if God compels them, then their actions are not free.  (If God gives creatures freedom, then what they do is in an important sense not up to God.)  Maybe so, says Mackie.  But surely there are possible worlds in which all creatures blessed with significant moral freedom in fact always freely do what’s right.  They have the sorts of moral choices that you and I have, but when they face those situations they, unlike you and me, always freely make the right choice.  In a world like that (and assuming that the world contains no floods, famines, or incurable disease), creatures enjoy morally significant freedom, but there is no evil.  If God exists, God must create such a world; since such a world is not actual, it must be that God does not exist.

Enter Plantinga’s free will defense.  The intent is to show that it is possible that God in fact couldn’t create a world with freedom but no evil.  To do so, Plantinga first asks us to ponder the property of transworld depravity (not to be confused with the Calvinist notion of total depravity).  If a person, Hugh, suffers from transworld depravity, then for any world God could create, if God puts Hugh in it (and gives Hugh morally significant freedom) then Hugh will freely sin at least once, thereby introducing or contributing to the evil in that world.  So, if God wants to create a world with freedom but no evil, God knows that Hugh is one person he can’t put in it.

The thing to see is that it’s possible for there to be people like Hugh who suffer from transworld depravity and, if they do, there is nothing God can do about that.  What people will freely do in any particular set of circumstances is not up to God.  As we have said, God can’t compel Hugh to freely do what’s right.  God could, however, refrain from creating Hugh; and if God wants to create a world with freedom but no evil, God might very well do that.

But if it’s possible for Hugh to suffer from transworld depravity, it is also possible that every single person that God could create suffers from it.  And note what would happen if this possibility were actual:  then God would be unable to actualize a world in which there is freedom but no evil.  There would be no one whom God could put in it!  Since this is possible, it’s possible that God couldn’t create a world like the one Mackie said God would if he existed.  But if God couldn’t create a world like that, must he refrain from creating altogether?  Surely not:  a world with freedom and some evil may be a sufficiently good one for God to create.  And if so, then we have established what we set out to do:  it is possible for God to create a world with evil; therefore, it’s possible for God and evil to co-exist.6

Plantinga’s development of the free will defense had two important consequences (aside from establishing him as a first-rate Christian philosopher).  First, it put to rest Mackie’s bold claim that evil is incompatible with God’s existence and moved opponents of theism back to the weaker claim that the evil we see constitutes evidence against God’s existence.  (Plantinga has had quite a bit to say about that issue as well.)  Second, in drawing out the free will defense Plantinga re-invented and defended the theory of divine providence known as Molinism.  According to Molinism, God knew prior to creating the world what free choices creatures would make in any situation that God might place them in.  You can see the role that this theory plays in the free will defense:  if God is to know that every creature he could possibly create suffers from transworld depravity, God has to have knowledge of what free choices they would make before God creates them (and of course before they make those choices).  Molinism and other theories of divine providence have been the subject of much debate among theists in recent years, and the current interest in Molinism was largely triggered by Plantinga’s work on the free will defense.7



While much of Plantinga’s early philosophical work had centered on issues in metaphysics (and he had, impressively, brought issues of importance to Christians to the forefront of that field), starting in the 1980s he turned more toward questions in epistemology.  He was especially interested in the question of whether belief in God could be justified or rational.  A common view, accepted in philosophical circles and elsewhere, is that theistic belief can be justified only if it is based on good evidence—usually interpreted to mean good arguments.  It is also commonly held that there is no such evidence, and hence that belief in God unjustified, irrational, and perhaps such that those who hold it should be ashamed of themselves.

Theists who hope to defend the rationality of belief in God have generally responded to this challenge in two ways.  First, they have attempted to construct compelling arguments for God’s existence.  Second, they have tried to show that belief in God need not be based on arguments in order to be rational.  While Plantinga believes that some of the arguments for God’s existence are quite powerful, he nonetheless recognizes that very few theists believe on the basis of those arguments.  (Indeed, rather few even have access to them or understand them.)  Thus Plantinga’s main aim has been to develop the second response.  He argues that belief in God can be properly basic, meaning that a person can be perfectly justified in believing in God without believing on the basis of arguments.  Or, to put it more simply, theistic belief should be considered innocent until proven guilty.

One of Plantinga’s main arguments for this conclusion begins with some observations about perceptual beliefs.  Beliefs like there are people in the room or there is a computer in front of me are perceptual beliefs that are naturally and immediately produced in us under certain conditions.  We do not hold them on the basis of arguments.  No one walks into a room and thinks to herself, “I am having a people-like visual experience; usually when I have such an experience, there are people in front of me; therefore, there are people in front of me.”  We all have better things to do with our time.  Instead, when we walk into a room and find ourselves with that sort of visual input, our cognitive faculties automatically and without reflection produce in us various beliefs about our environment including, for instance, that there are people in the room.  And the resulting beliefs are justified, even though we don’t hold them on the basis of arguments.

The next step in Plantinga’s argument involves comparing perceptual beliefs to beliefs about God.  Beliefs such as “God is unhappy with me” or “God is to be praised” or “I need God’s help” often well up within us as automatic responses to circumstances—just like perceptual beliefs do, Plantinga argues.  Such theistic beliefs are not arrived at on the basis of argument; but that should be no obstacle to their being justified, since the same is true of perceptual beliefs and no one complains about them!  Plantinga’s suggestion, then, is that just as perceptual beliefs are justified even though they are not held on the basis of arguments, so are beliefs about God.

Plantinga’s view that belief in God is innocent until proven guilty (a view that is part of what he called “Reformed Epistemology”) has been enormously influential and much debated.  Some critics have argued that while some beliefs are such that it is appropriate to hold them without doing so on the basis of an argument, belief in God is not among them.  But those who want to push this objection need to present a criterion for what beliefs a person can justifiably start with, a criterion that theists ought to accept and that is such that belief in God doesn’t meet it.  Plantinga has himself considered and rejected one such criterion (a theory he called “Classical Foundationalism”), and the prospects for this response do not look good.

Other critics have granted that belief in God may be innocent initially (for children and others who lack intellectual sophistication), but claim that it has been proven guilty, since there are all sorts of reasons for thinking that God does not exist.  Here again, however, the burden is on the critic to show that those reasons are genuinely compelling and such that theists should accept them.  Plantinga and other Christian philosophers have done a great deal to counter the attacks on theism that these critics have presented.

One final and important note:  some of Plantinga’s landmark work during the 1990s involved further development of the idea that Christian belief can be justified—and can in fact amount to knowledge—without being based on arguments.  In his first two Warrant books he develops a comprehensive theory of knowledge (and critically evaluating other theories currently on offer), and in Warranted Christian Belief he turns to showing how Christian beliefs about the Incarnation, Resurrection, and so forth can meet the conditions for knowledge.  In short, Plantinga argues that a true belief amounts to knowledge if and only if it is produced by properly functioning faculties that are reliably aimed at truth.  We can see how this works for my visual belief that there is a computer in front of me.  That belief is produced by my visual faculties; the aim of my visual faculties is to give me true beliefs; those faculties do that well (I have good eyesight) and they are functioning well now.  If so, and if there really is a computer in front of me, my belief amounts to knowledge.

Now apply this to belief in God.  Plantinga, following John Calvin, suggests that God has created us with a sensus divinitatus (“sense of the divine”), a faculty that naturally produces in us beliefs about God and enables us to recognize God’s work in the world for what it is.  (It would not be at all surprising for God to give us such a faculty, rather than having our knowledge of him depend on understanding and accepting the complex and controversial proofs of God’s existence.)  If so, then our beliefs about God can amount to knowledge in the same way that my visual beliefs do.  And with more specifically Christian beliefs, if they are, as Aquinas and Calvin believed, “revealed to our minds and sealed on our hearts” by the Holy Spirit, then those beliefs amount to knowledge as well.  (And thus the popular idea that faith and knowledge are fundamentally different or somehow opposed to each other is mistaken.)  Plantinga’s conclusion in Warranted Christian Belief is that anyone who wants to claim that Christian belief is irrational or doesn’t amount to knowledge is going to have to show first that Christian belief is false.  That is no easy task, and again Plantinga himself and many other Christian philosophers and scholars have stood ready to respond to attacks of that sort.




While much of Plantinga’s writing has involved defending Christian belief, perhaps his most famous argument in recent years has been his argument against evolutionary naturalism.8  It isn’t news that many people consider theism irrational, but Plantinga argues instead that naturalism—the view that no God or any supernatural being exists—deserves that designation, because any naturalist who reflects on the origin of her cognitive faculties should come to doubt everything she believes, including naturalism itself.

The argument, briefly, goes like this.  If naturalism is true, then it must be that human beings came to exist by way of the process of evolution, and more particularly by random genetic mutation acted on by natural selection.  This process is responsible for all of our traits and capacities, including, for example, our cognitive faculties.  Now, an important thing to recognize about this process is that it is concerned with our behavior, rather than with what we believe.  If a tiger is after you, it’s what you do rather than what you believe that’s going to enable you to survive (or not).  You could believe all sorts of crazy things, but if it results in appropriate tiger-avoidance behavior, then you pass that particular evolutionary test.  This means that our cognitive faculties were not selected by the evolutionary process because they helped us get in touch with the truth; instead, they were selected fundamentally because they helped to survive (or because they came along with survival-enhancing traits).  But this raises a question:  if that is how our cognitive faculties came to be, what is the likelihood that our cognitive faculties actually do get us true beliefs?  How probable is it that they are reliable?

Not surprisingly, Plantinga answers his own question:  the probability is in fact quite low (or else it’s inscrutable—we just can’t tell what it is).  To see this, consider the following two possibilities about the way our beliefs and our behavior may be linked:  either (1) our beliefs actually impact our behavior (as we usually think—we usually think that the fact that you believe that your car is in the parking lot causes your body to walk over there), or (2) they don’t.  Now as a matter of fact naturalists have a horrible time explaining how beliefs could impact behavior, and it seems that on naturalism (oddly enough) there is a reasonable chance that they don’t.  And if that’s right, then evolution would be completely blind to what we believe, and then the probability that our cognitive faculties get us reliably in touch with the truth would be extremely low.

On the other hand, if our beliefs do impact our behavior (as common sense dictates but naturalism has enormous difficulty accounting for), then it’s somewhat more likely that our faculties are reliable.  But there still is a decent chance that they are unreliable since it seems that there are all sorts of false beliefs that we could have that would nevertheless contribute to behavior that helps us to survive.  (In Plantinga’s example, I could believe that a tiger signals the start of a race, and so as soon as I see one I run as fast as I can in the other direction.  My belief would be false, but it would help me survive.)  So on that option the probability that our faculties are reliable is only moderately high.  Supposing for now that given naturalism it is just as likely that our beliefs impact our behavior as that they don’t, we should average the probabilities that our faculties are reliable on each option in order to determine the overall probability, on naturalism, that our faculties are reliable.  The average of “extremely low” and “moderately high” is still “quite low”; and this is exactly Plantinga’s conclusion.

But now the naturalist has a problem.  For it seems that anyone who has this sort of reason to think that her cognitive faculties are unlikely to deliver her true beliefs should refrain from believing anything that her cognitive faculties tell her—which is anything she believes, including naturalism and evolution!  It would be irrational for her to continue to trust the deliverances of faculties she believes are unreliable!  (It would be just like you believing the testimony of a friend you think lies most of the time.)  So, Plantinga concludes, it is in fact naturalists, saddled as they are with an evolutionary account of the origin of our cognitive faculties, who are irrational with every belief that they hold.9



Finally, Plantinga has done much to challenge Christian scholars to take their faith commitments seriously when doing their academic work.  We Christians don’t need to spend all our time simply defending Christian belief from attack, Plantinga argues.  We should also boldly step forward and explore how the world looks from a Christian point of view.  Many in the academic world may frown on such scholarship, but we need not allow our projects to be dictated by them.  Our responsibility as Christians is to Christ and his Church.  Besides, why would we want to set aside our Christian beliefs when doing are scholarly work?  There may be times when it is appropriate to do so, but in general if we want to arrive at the truth we should take into account all that we know, including what we know by faith.  Thus we should actively seek to apply our faith in our academic work.

Of course, this is a real challenge in many fields, and perhaps especially in the sciences, where conflicts with the Christian faith seem everywhere present.  Becauseof this, Plantinga himself has spent much time in recent years working on the relation between science and religion.10  He has focused especially on areas of science where it seems that profoundly anti-Christian assumptions often come into play.  One example is the field of evolutionary psychology.  Many evolutionary explanations of religious or moral behavior assume at the outset that Christian belief is false and that morality is not deeply rooted in reality.  Another example involves the more general way in which scientists who endorse methodological naturalism as the proper scientific way to explain natural phenomena (where methodological naturalism forbids any appeal to supernatural activity) occasionally slide from that to metaphysical naturalism (the view that in fact no supernatural beings exist) and act as though that is required for right-minded scientists.  Christians need to see where such moves are being made and recognize that they don’t need to blindly accept those assumptions themselves.  Unearthing such assumptions has been an important project of Plantinga’s, as has been exploring the issue of whether Christians who do science really ought to feel constrained by the dictates of methodological naturalism.11



Plantinga’s influence on Christians in philosophy is difficult to overstate, both because of his own important work and because of the way that he has mentored and supported the development of aspiring young Christians scholars.  Eleonore Stump, herself an exceptional Christian philosopher currently teaching at Saint Louis University, once gave a guest lecture in one of Plantinga’s classes on what a Christian philosopher should be like.  She began her talk by saying that she might most effectively answer her question by simply pointing at Plantinga.  Many of Plantinga’s students and friends feel the same way.  Plantinga embodies what a Christian in philosophy, or in academia, or in life more generally, should be like.  He is courageous, hard-working, gracious, witty, humble, and gifted with a magnificent sharpness of mind that he has used with great success in the service of Christ and the Church.



Raymond J. VanArragon received his PhD in philosophy in 2002 from the University of Notre Dame, where he studied under Alvin Plantinga.  He is now Assistant Professor of Philosophy at Bethel University in St. Paul, Minnesota.

( This article was first published in the May-June 2006 Areopagus Journal)



1 April 7, 1980.

2 Smith’s article, “The Metaphilosophy of Naturalism,” was published in the Fall 2001 issue of Philo.

3 Plantinga has authored both an ‘intellectual’ and ‘spiritual’ autobiography.  The former is found in Alvin Plantinga, eds. James E. Tomberlin and Peter van Inwagen (Dordrecht:  D. Reidel Publishing, 1985); the latter is found in Philosophers Who Believe, ed. Kelly James Clark (Downers Grove, IL:  InterVarsity Press, 1993.)  Much of this account of Plantinga’s life is taken from these writings.

4 That story did not make it into either of Plantinga’s autobiographies.  Instead, he told me about it a few years ago after I asked him to direct my dissertation and then described how nerve-wracking the process of asking him had been.  It turned out that he had never been in a similar situation.

5 Some of Plantinga’s colleagues at Wayne State included Hector Castaneda, Edmund Gettier, Keith Lehrer, and Robert Sleigh, all of whom would become highly accomplished philosophers.

6 It’s very important in assessing the free will defense to note that Plantinga is not saying that every person God could create actually does suffer from transworld depravity; he is only claiming that it’s possible for it to be the case that every person God could create suffers from it.  (And hence it’s possible for God to be unable to create a world with freedom but no evil.)  Plantinga has often been misunderstood on just this point.

7 Thomas Flint, himself the author of an excellent book explaining and defending Molinism, has referred only half in jest to Plantinga’s The Nature of Necessity as a “Molinist holy book.”

8 For critical discussion of this argument, and Plantinga’s replies, see Naturalism Defeated?  Essays on Plantinga’s Evolutionary Argument Against Naturalism, ed. James Bielby (Ithaca, NY:  Cornell, 2002).

9 Note that a Christian who believes that God used the process of evolution to produce us does not face a similar problem.  If God guided the process of evolution, no doubt God ensured that our cognitive faculties would turn out reliable.

10 In 2005, Plantinga delivered the famous Gifford Lectures at St. Andrews in Scotland.  The title of his lectures was “Science and Religion: Conflict or Concord?”

11 Plantinga’s many papers on these topics include “Methodological Naturalism?” which can be found on the web at