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January 18, 2005

Plantinga's Epistemology

Since Raul recently wrote an excellent piece touching on how important it is to know why you know -- and since I'm trying to insert old TG.com stories into the new archive -- what follows is a reprint of my retrospective on noted philosopher of religion Alvin Plantinga. (More current stuff on the subject can be had at Certain Doubts, which is possibly the most abstruse blog in existence.)

Recently I wrote someone a check for $500. I believed it would clear because my bank account had over $500 in it. I said to myself, "I know this check will clear." And it did actually clear. However, I discovered two things after the check cleared: 1) I mistakenly wrote the check from the wrong account, which did not, at the time of writing, have $500 in it; and 2) unbeknownst to me, my tax refund was directly deposited in that account the day before the check cleared, bringing its balance above $500. So even though I had good reason to believe something would happen and it did, I didn't know it was going to. (By the way, this is an excellent reason why a greedy application of Ockham's Razor isn't advisable. The most parsimonious explanation for the check clearing would not have been the truth.) This sort of accidental problem of knowledge is called a Gettier problem, after Edmund Gettier, who wrote a hugely influential paper simply titled "Is Justified True Belief Knowledge?" Now many, many people have written responses to that paper, because before Gettier it was generally believed that knowledge equaled justified true belief (though Wittgenstein had touched on it previously, albeit unceremoniously). Quite of few of them would fix my Gettier problem by saying that my justification was not really justification at all. But if my justification was not sufficient, how much more careful should I have been? Do I have to be able to justify everything I know? And what do I mean, exactly, when I say I'm "justified" in believing something?

In Warrant: The Current Debate and Warrant and Proper Function, Plantinga explored the nature of what he calls "warrant," that stuff which transmutes true belief into knowledge. He argued that the JTB paradigm, by philosophical standards a relative newcomer born of the Enlightenment, is inherently normative; to be justified is merely to do one's epistemic duty, and to do otherwise is to invite ridicule for being irrational. Moreover, he showed that the noetic system that held to JTB, classical foundationalism, was itself irrational by its own standard. How was this accomplished? Well, classical foundationalism places an epistemic burden on every rational animal: if you say you know something, you had better have a good reason; and for every reason, you had better have a good reason for that, too; and so on, until you reach an unimpeachable epistemic core of beliefs which, being "properly basic," simply could not be false. So, in principle, for every proposition you accept, you should be able to explain how it was derived from such obviously true statements as

2 + 2 = 4


All men are mortal, and Socrates is a man, therefore Socrates is mortal.

But, Plantinga asked, what about the proposition

For every proposition you accept, you should be able to explain how it was derived from such obviously true statements as '2 + 2 = 4' or 'all men are mortal, and Socrates is a man, therefore Socrates is mortal,'

which one must accept if classical foundationalism is the correct way to view knowledge? Is it properly basic? Surely not. Nor does it proceed from properly basic statements, however indirectly. Thus, he concluded, there is something wrong with classical foundationalism at its core.

Plantinga has become famous in philosophical circles for such petard-hoisting feats of logic. In his early work, The Nature of Necessity, he tackled the esoteric field of modality with humor and aplomb ("Could Socrates have been an alligator?" asks one section on the potentialities of possible worlds), building up principles to be used in the ontological argument (God must exist in all possible worlds) and the problem of evil. Plantinga further elaborated these positions (among others) in God, Freedom, and Evil and God and Other Minds, and restated them in his third volume on warrant, Warranted Christian Belief. The last makes an impressive case for the rationality of theism in general and for Calvin's instigation of the Holy Spirit, the sensus divinitatus, as the external motivator of such belief. He maintains that through this mechanism, one can know that God exists in way that is properly basic. But since evidence is not required for theistic belief, neither can one expect to bludgeon an unbeliever into belief using evidence, however impressive. This theory of knowledge, known as "reformed epistemology," has played an essential role in the development of so-called "negative apologetics" that defend faith against charges of incoherence and irrationality. At the same time, it has refocused efforts on positive apologetics that approach evangelism with an understanding of how one changes their beliefs. (For a sampling of such work, I recommend the essay collection Reason for the Hope Within.)

I hold Alvin Plantinga in very high esteem, but I can't say agree with everything he's ever said. I'll close with some remarks on his recent work.

Plantinga has lately focused on two items: the problems of naturalism within science; and the consequent need for a replacement, "Augustinian" science that respects "what we know as Christians." In this, he is at least peripherally allied with the Intelligent Design movement. As a Christian who is also a scientist, I can identify with his feeling that there ought to be some way of connecting the two, though I'm not sure it will be widely regarded as "science." But I'm more concerned about his naturalism argument. Frankly, his probabilistic attack on naturalism through "Darwin's Doubt" seems itself rather dubious. The argument put forward by Plantinga, dating in part back to Darwin, states that one's own beliefs cannot be trusted if evolution is true, since evolution has no intrinsic interest in producing organisms that produce consistently true beliefs. He believes that the likelihood is low that evolution produced such a mechanism, therefore the only way we can believe what our own minds are telling us is to embrace theism, which provides an explanation for our rationality. Naturalists argue that, in fact, the likelihood is high; so the argument as formulated amounts, I fear, to yet another God-of-the-gaps position that erodes people's confidence in theism.

A probabilistic attack appears even less promising given that, in previous work, Plantinga set out to prove (!) that Christianity cannot be defended based on its probability and must be accepted as properly basic through sensus divinitatus -- which was installed within us by "God or evolution or both," as he is fond of saying. This anti-evidentialist position is supremely important for Plantinga's entire system of philosophy. So why would he do violence to it, in the face of tremendous consensus on evolution, by asserting that if evolution is true, then no such belief-producing mechanism is possible? Perhaps the opportunity to do some more petard-hoisting was simply irresistible, especially when considering the sanctimony of his naturalist opponents. The trouble is that evolution is true, even if naturalism isn't. There was no need for Plantinga to step into this mess, absent his logician's skepticism. There are already theistic evolutionary paradigms in which a sensus divinitatus could be said to develop because it gave certain creatures an advantage (see for example Teilhard or Dobzhansky). He might even say that the evolution was not directed toward particular body plans but that this aspect of the process was, as they say, "ineluctable" and resulted in creatures that could both 1) rule their environment and 2) know God in a basic way. It was this creature that God created in His image, and in our world, that creature is man. In one of Plantinga's possible worlds, maybe all of us, even Christ, was an alligator...

Posted by The Greatness at January 18, 2005 03:11 AM