The theory of knowledge is currently flourishing, perhaps as never before. There are some, of course, who loudly proclaim the death of epistemology. This seems to me less premature than confused: what they observe is the breakdown of classical foundationalism, which is only one epistemological program among several, even if a historically important one. Confounding species with genus, they shrilly announce the demise of the latter. It is as if someone, noting the demise of Eastern European communism, should proclaim the death of political systems and government generally.

There is some excuse for this confusion. Classical foundationalism has been dominant in Western epistemology ever since the Enlightenment; more broadly and more exactly, it is really classical deontologism—the view that epistemic responsibility and fulfillment of epistemic obligation and duty are of crucial epistemic importance—together with its consequent internalism that has been thus dominant. Although classical foundationalism has fallen into ruins in the last half of the present century, the same most emphatically cannot be said for classical deontologism and internalism.

Nevertheless, one of the most exciting developments in twentieth-century theory of knowledge is the rejection of deontology and the sudden appearance of various forms of externalism. More precisely, this development is less the appearance than the reappearance of externalism in epistemology. Externalism goes a long way back, to Thomas Reid, to Thomas Aquinas—back, in fact, all the way to Aristotle. Indeed, we may venture to say that (apart, perhaps, from Augustine and some of the skeptics of the later Platonic Academy) internalists in epistemology are rarae aves in Western thought prior to Descartes. It is really externalism, in one form or another, that has been the dominant tradition; internalism is a recent interloper. We may therefore see present-day externalists as calling us back to our first epistemological love, after a brief and ill-starred fling with the seductive siren of internalism. In this book and its sequels, I hope to heed that call.

My topic, therefore, is the theory of knowledge. In the theory of knowledge, naturally enough, we try to come to some understanding of knowledge. But where and how shall we start? First, there is nearly universal agreement that knowledge requires truth; a person knows that all men are mortal only if it is true that all men are mortal. Of course we sometimes use the term ‘knows’ as if it were within ironic quotes, as when we say that a good Marxist knows that the idea of objective truth is no more than a piece of bourgeois sentimentality. Sociologists of knowledge sometimes seem to take this ironic use of the term as its basic use, so that ‘S knows P’, as they use it, means little more than that S believes P, or is strongly convinced of P, or perhaps is committed to P, or is such that the scientists of his culture circle announce P. But let us set such aberrant notions aside, for the moment, and agree that knowledge requires truth. Second, it is widely (though not universally1) agreed that knowledge, whatever precisely it is, also involves belief; a person knows that all men are mortal only if, among other things, she believes that all men are mortal (where here the term ‘believes’ is to be taken in the classical sense of ‘thinking with assent’; it does not imply lack of certainty or mere belief).

There is wide agreement that knowledge requires true belief; but as far back as Plato's Theaetetus, there is also recognition that it requires more. I may believe that I will win a Nobel Prize next year; by some mad chance my belief may be true; it hardly follows that I know the truth in question. What more is required? What is this elusive further quality or quantity which, or enough of which, stands between knowledge and mere true belief? What is it that, added to true belief, yields knowledge; what is it that epistemizes true belief? (We cannot properly assume that it is a simple property or quantity; perhaps it is more like a vector resultant of other properties or quantities.) This quality or quantity, however, whatever exactly it may turn out to be, is the subject of this book and the sequels, Warrant and Proper Function and Warranted Christian Belief. Contemporary epistemologists seldom focus attention on the nature of this element (although they often ask under what conditions a given belief has it); and when they do, they display deplorable diversity. Some claim that what turns true belief into knowledge is a matter of epistemic dutifulness, others that it goes by coherence, and still others that it is conferred by reliability. I shall argue that none of these claims is correct, and (in Warrant and Proper Function) suggest a more satisfactory alternative.

Epistemology is extremely difficult, in many ways more difficult than, say, the metaphysics of modality. The latter requires a fair amount of logical acumen; but it is reasonably easy to see what the basic concepts are and how they are related. Not so for epistemology. Warrant, justification, evidence, epistemic normativity, probability, rationality—these are all extremely difficult notions. Indeed, each of those terms is really associated with a whole class of difficult and analogically related notions, where a big part of the difficulty is discerning how the members of each class are related to each other and to the members of the other classes. Coming to clarity on them and their relatives and discerning the relations among them is strenuous and demanding; yet it is the only way to progress in epistemology. What is needed is hermeneutics, understanding, interpretation. Here the way to progress is not to turn directly to the issue itself, proceeding in lofty abstraction from what others have said and thought on the matter. There is an impressive tradition on these topics, going back to the beginnings of modern philosophy and indeed to the beginnings of philosophy itself. Furthermore, epistemology is at present in lively ferment; there are many penetrating and imaginative contemporary contributions to this and neighboring issues; it would be at best churlish to ignore them. Still further, it is unsatisfactory to consider only, say, coherentism überhaupt; for while we may thus come to understand coherentism taken neat (the Platonic Form of coherentism, we might say), any flesh-and-blood coherentist will have her own additions and subtractions, her own modifications, which may result in a position stronger (or weaker) than coherentism as such, and in any case may make a real contribution to our understanding of the issues. My ultimate aim is to come to a satisfying and accurate account of warrant; but to do so we must first pay close attention to what our contemporaries suggest (concurring where possible, opposing where necessary).

I begin with internalism, the tradition dominant since the Enlightenment. First, there is the carefully crafted foundationalist internalism of Roderick Chisholm (chapters 2 and 3). To understand Chisholm and other internalists properly, however, we shall have to make a preliminary excursus (chapter 1) into the classical internalism of Descartes, Locke, and others; here we note the roots of internalism in epistemic deontology, the view that epistemic duty and obligation are of crucial epistemic importance. After Chisholmian internalism I turn to coherentism. For classificatory purposes, I take it as a form of internalism; and in the next three chapters I consider coherentism überhaupt (chapter 4), the coherentist views of Laurence BonJour (chapter 5) and contemporary Bayesian versions of coherentism (chapters 6 and 7). Third (chapter 8) there is the more attenuated internalism of John Pollock; I see Pollock's view as in transition from internalism to externalism.

After arguing that internalism, classical or otherwise, holds no real promise for a correct account of warrant, I turn to externalism. Given the recent history of epistemology, externalism seems new, innovative, perhaps even radical; on a longer view, however, internalism is a departure from the main tradition in Western epistemology, which, as I noted, has been externalist. The dominant form of contemporary externalism is reliabilism; I consider (chapter 9) the reliabilist views of William Alston, Fred Dretske, and Alvin Goldman. Reliabilism has its charms; but it omits a crucial component of warrant (or so, at any rate, I shall argue): that of proper function or absence of dysfunction. The idea of our cognitive faculties’ functioning properly in the production and sustenance of belief is absolutely crucial to our conception of warrant; this idea is intimately connected with the idea of a design plan, a sort of blueprint specifying how properly functioning organs, powers, and faculties work. The last chapter offers a preview of coming attractions: a brief and preliminary account of that elusive notion warrant, an account that seems at once subtler, more accurate, and more satisfying than any of the theories in the field.

In the second volume, Warrant and Proper Function, I shall outline this theory in more detail. The first two chapters will be a general development of the theory, involving in particular an examination of the notion of proper function and its colleagues: purpose, damage, design plan, malfunction, and the like. Then in the next eight chapters I shall explore general features of our cognitive design plan, explaining how my account of warrant applies in each of the main areas of our epistemic establishment: knowledge of myself, knowledge by way of memory, knowledge of other persons, knowledge by way of testimony, perception, a priori knowledge and belief, induction, and probability. Then comes a chapter on a more general or structural feature of our epistemic establishment: the question whether warrant has a foundationalist structure. Finally, in the last two chapters of Warrant and Proper Function I argue that naturalism in epistemology flourishes best within the context of supernaturalism in theology or metaphysics: the prospects for a naturalistic epistemology are intimately intertwined with a theistic view of the world. I therefore conclude that naturalistic epistemology is indeed viable; it offers the best chance for success; but only if set in the context of a broadly theistic view of the nature of human beings.

It would be nice to have a name for this theory. ‘Proper Functionalism’ comes to mind; it has the advantage of a certain pleasing ambiguity, as well as the advantage that a view whose name contains ‘Functionalism’ gets (at present) an automatic leg up. ‘Proper Functionalism’, however, does not come trippingly off the tongue and I am inclined to prefer ‘The Theory of Proper Function’ a name suggested by William Hasker. Whatever we call it, the theory in question is, broadly speaking, an example of epistemology ‘naturalized’. This account of warrant is in some ways similar to that of Thomas Reid; at any rate it is in the spirit of Reid's work (as perhaps also in the spirit of Aquinas and Aristotle). Of course, I am not entering the lists in order to provide a good or satisfactory interpretation or account of Reid's thought.

The projected (but so far unwritten) third volume of this series, Warranted Christian Belief, will be an application of the theory developed in Warrant and Proper Function to Christian and theistic belief. Although these three volumes form a sort of series, they are designed to be self-contained and can be read separately.

The three volumes together develop the ideas underlying my Gifford Lectures in Aberdeen in 1987 and my Wilde Lectures in Oxford in 1988. I am grateful to both sets of electors for the honor of the invitations, and for giving me an opportunity to work out these ideas. Given the debt my views owe to Thomas Reid, it was gratifying and interesting to be able to lecture on them at Aberdeen, only a few miles from his birthplace, and the scene of his early work. I should also like to thank Professors Robin Cameron and James Torrance and the other members of the philosophy and theology departments at the University of Aberdeen, for their wonderful hospitality during the months my wife and I visited there. I must express similar gratitude to Professor Richard Swinburne for similar hospitality during our stay in Oxford.

These ideas also played a prominent part in Payton Lectures at Fuller Theological Seminary in 1987, Norton Lectures at Southern Baptist Seminary in 1988, lectures at the 1986 Wheaton Philosophy Conference, and lectures at the 1986 NEH Summer Institute for Philosophy of Religion in Bellingham, Washington; I am extremely grateful to all of these audiences (but perhaps particularly the participants in the NEH Summer Institute) for criticism and stimulation, from which I benefited greatly. I am also grateful to the National Endowment for the Humanities for a Fellowship for 1987 and to the University of Notre Dame for sabbatical leave for the same year.

In writing these books I have received a great deal of help from many people; I am grateful to them all for penetrating criticism, stimulating discussion, and wise counsel; without their help these books would have been much the poorer. Indeed, the number of people from whom I have received help is embarrassingly large (with so much help from so many people, why aren't these books better than they are?) I must make special mention of Felicia Ackerman, William Alston, Robert Audi, Laurence BonJour, Roderick Chisholm, Robin Collins, Marian David, Michael DePaul, Fred Dretske, Aron Edidin, Richard Feldman, Richard Foley, John Foster, Carl Ginet, Lee Hardy, William Hasker, Kenneth Konyndyk, Patrick Maher, George Mavrodes, Caleb Miller, Richard Otte, Michael Partridge, John Pollock, Philip Quinn, William Ramsey, Del Ratzsch, Bruce Russell, James Sennett, Thomas Senor, Robert Shope, Caroline Simon, Ernest Sosa, Leopold Stubenberg, Richard Swinburne, Fred Suppe, Bas van Fraassen, Edward Wierenga, Nicholas Wolterstorff, Stephen Wykstra, and Dean Zimmerman. Some of these—BonJour, Collins, Dretske, Russell, Senor, Suppe, van Fraassen, and Zimmerman, for example, but especially Alston—went so far as to give me extensive and detailed written comments on various portions of the manuscripts; to them I am particularly grateful. Others—the members of the Notre Dame Monday Colloquium Group and the Calvin College Tuesday Colloquium group—discussed and criticized parts of these books over periods of many months; to them also I am especially grateful. I have learned more than I can say from discussion with all of these people and their comments on various parts of the manuscripts. No doubt many will see that their criticisms aren't properly met and their insights not properly incorporated (or worse, not properly acknowledged); to them I can only apologize.

Large parts of chapter 1 appeared in Philosophy and Phenomenological Research; I am grateful to the editors for permission to republish them here. Parts of chapter 2 appeared in Philosophical Analysis: A Defense by Example, edited by David Austin (Dordrecht and Boston: Kluwer Academic Publishers, 1988).

Finally, I must express special gratitude to Martha Detlefsen, who did her formidable best (against nearly insurmountable odds) to keep both me and these books properly organized.

A. P.

Notre Dame, Indiana

April 1992

• 1. For a discussion of dissenters, see Robert Shope, The Analysis of Knowing (Princeton: Princeton University Press, 1983), pp. 171–92.