Traditionally epistemology sets itself a number of tasks. It seeks to specify principles of epistemic justification, and to justify those principles. Given that those principles are justified, it further seeks to establish what kinds of claims we can know or justifiably believe. This last task traditionally involves addressing sceptical challenges to our possession of knowledge or justified belief. When evaluating an account of naturalized epistemol-ogy, we need to consider which (if any) of these tasks it undertakes and in what form it undertakes the task.
Quine’s project of naturalized epistemology has a negative and a posi-tive component. The negaposi-tive component is about how epistemology has been done to date. The positive component is about how epistemology should instead be done. Take these components in turn.
As Quine sees it, traditional epistemology requires that knowledge had foundations. These foundations are supposed to be beliefs that are justi-fied but which are not justijusti-fied by other beliefs. Traditional epistemology explores which beliefs are foundational in this sense. Suggestions about which beliefs count as foundational beliefs include certain perceptual beliefs and beliefs about one’s current experiences. Traditional epistemol-ogy also requires that there are certain epistemic principles that show how justification can be transmitted from foundational beliefs to other beliefs.
Non-foundational beliefs are to be justified by being derived from the foundational beliefs via these epistemic principles. Traditional epistemol-ogy then seeks to show how all and only justified beliefs belong to a struc-ture as so described. These beliefs would either be foundational beliefs, or beliefs suitably related by the epistemic principles to foundational beliefs.
The goals of traditional epistemology are to show what a justified belief is, which beliefs count as justified because of their place in a foundational structure, and how to improve our set of beliefs — which beliefs to retain and which to revise. A particular challenge to the traditional epistemolo-gist’s project is posed by scepticism about justification: the view that few, if any, of our beliefs are justified. Traditional epistemology seeks to rebut this scepticism. Quine takes the project of traditional epistemology to run from Descartes (1641) to at least Carnap (1928). (We should not overlook, though, the major differences between the epistemologies of philosophers such as Descartes and Carnap. Carnap took perceptual experiences to be among the foundations of knowledge. Descartes did not. As noted above, his foundations consisted only in what he took to be truths that are immune to doubt and self-evident to the intellect.)
The negative component of Quine’s naturalized epistemology is the claim that traditional epistemology is a failed research programme. No beliefs qualify as foundational in the requisite sense, and no epistemic principles show how all of our other justified beliefs could be derived from the usual candidates for foundational beliefs. Quine does not offer sup-porting arguments for those claims. At the time of writing he may have thought that they did not need to be given and that the anti-foundation-alist lessons had already been learnt by philosophers. Whatever Quine’s thinking, the foundationalist project should not be lightly dismissed. A foundational belief need only be a justified belief that is not justified by other beliefs; it need not be indubitable (immune to doubt) or incorrigible (immune to error). Criticisms of foundationalism on the grounds that no
beliefs have the latter features are misguided (Alston 1976). Furthermore, foundationalism need not require that non-foundational beliefs are justi-fied only if they can be derived from foundational beliefs. It is open to foundationalism to allow weaker evidential relations to hold between foundational and non-foundational beliefs.
Our chief concern, however, is with the positive component of Quine’s naturalized epistemology. Let’s turn to that. This component consists in an alternative to the foundationalist project. Having renounced the goal of providing foundations for science and common sense, Quine writes that:
… epistemology still goes on, though in a new setting and a clarified status. Epistemology, or something like it, simply falls into place as a chapter of psychology and hence of natural sci-ence. It studies a natural phenomenon, viz., a physical human subject. This human subject is accorded a certain experimen-tally controlled input-certain patterns of irradiation in assorted frequencies, for instance, and in the fullness of time the sub-ject delivers as output a description of the three-dimensional external world and its history. The relation between the mea-gre input and the torrential output is a relation that we are prompted to study for somewhat the same reasons that always prompted epistemology; namely, in order to see how evidence related to theory, and in what ways one’s theory of nature tran-scends any available evidence. (Quine 1969b, 82–83)
In the above passage Quine is making a recommendation about the direction that epistemology should take. But exactly what Quine is recom-mending is a matter of debate. One prevalent reading takes him to be rec-ommending the replacement of epistemology by psychology. In particular, he is taken to be recommending that we study the psychological processes underlying how our experiences cause our beliefs, and that we ignore eval-uative issues about whether these experiences provide evidence for those beliefs. Instead of studying whether our experiences support our beliefs, we study only how our experiences bring about our beliefs. Traditional epistemological issues about rationality and justification are thereby shelved.2 Nevertheless, it is doubtful whether this is an accurate reading of Quine’s views. Quine himself rejects the reading (Quine 1990, 19–21), and at about the same time that he was writing his paper “Epistemology
2 This reading is endorsed by Stroud (1984, ch. 6), Kim (1988, 390), Kitcher (1992), and Feldman (1998, 4–5, 23) among others.
Naturalized” Quine was co-authoring a book that was explicitly a book on normative epistemology (Quine and Ullian 1970).3
Instead of taking Quine to be advocating the thesis that psychology should replace epistemology, we might more fruitfully take him to be advocating the relevance of psychology to epistemology. The positive component of Quine’s naturalized epistemology involves two features.
First, there is the claim that epistemology can and should use the empiri-cal results of our best scientific theories, and, in particular, what psycho-logical theories have to tell us about how our beliefs are caused. As Alvin Goldman puts it:
In studying and criticizing our cognitive procedures, we should use whatever powers and procedures we anteced-ently have and accept. There is no “starting from scratch.” … (Goldman 1978, 522)
The second feature of the positive component of Quine’s naturalized epis-temology is that sceptical problems arise from within science:
… the skeptical challenge springs from science itself, and that in coping with it we are free to use scientific knowledge.
(Quine 1974, 3) Kornblith agrees:
It is because science shows us how various aspects of our com-mon-sense view of the world may be mistaken that we come to raise the question of whether we might be entirely mistaken in the way we view the world. But because this question arises from within science, it is perfectly appropriate to draw on the resources (e.g.) of science to answer it. (Kornblith 1995, 240-41) We will examine these two features of Quine’s positive component in the next two sections.