Epistemology

1. The normative answers: foundationalism and coherentism

The historically dominant tradition in epistemology answers that question by claiming that it is the quality of the reasons for our beliefs that converts true beliefs into knowledge (see Epistemology, history of). When the reasons are sufficiently cogent, we have knowledge (see Rational beliefs). This is the normative tradition in epistemology (see Normative epistemology). An analogy with ethics is useful: just as an action is justified when ethical principles sanction its performance, a belief is justified when epistemic principles sanction accepting it (see Justification, epistemic; Epistemology and ethics). The second tradition in epistemology, the naturalistic tradition, does not focus on the quality of the reasons for beliefs but, rather, requires that the conditions in which beliefs are acquired typically produce true beliefs (see Internalism and externalism in epistemology; Naturalized epistemology).

Within the normative tradition, two views about the proper structure of reasons have been developed: foundationalism and coherentism (see Reasons for belief). By far, the most commonly held view is foundationalism. It holds that reasons rest on a foundational structure comprised of ‘basic’ beliefs (see Foundationalism). The foundational propositions, though justified, derive none of their justification from other propositions. (Coherentism, discussed below, denies that there are foundational propositions).

These basic beliefs can be of several types. Empiricists (such as Hume and Locke) hold that basic beliefs exhibit knowledge initially gained through the senses or introspection (see A posteriori; Empiricism; Introspection, epistemology of; Perception, epistemic issues in). Rationalists (such as Descartes, Leibniz and Spinoza) hold that at least some basic beliefs are the result of rational intuition (see A priori; Rationalism). Since not all knowledge seems to be based on sense experience, introspection or rational intuition, some epistemologists claim that some knowledge is innate (see Innate knowledge; Knowledge, tacit; Kant, I.; Plato). Still others argue that some propositions are basic in virtue of conversational contextual features. That is, some propositions are taken for granted by the appropriate epistemic community (see Contextualism, epistemological).

Foundationalists hold that epistemic principles of inference are available which allow an epistemic agent to reason from the basic propositions to the non-basic (inferred) propositions. They suggest, for example, that if a set of basic propositions is explained by some hypothesis and additional confirming evidence for the hypothesis is discovered, then the hypothesis is justified (see Inference to the best explanation). A notorious problem with this suggestion is that it is always possible to form more than one hypothesis that appears equally well confirmed by the total available data, and consequently no one hypothesis seems favoured over all its rivals (see Induction, epistemic issues in; Goodman, N.). Some epistemologists have argued that this problem can be overcome by appealing to features of the rival hypotheses beyond their explanatory power. For example, the relative simplicity of one hypothesis might be thought to provide a basis for preferring it to its rivals (see Simplicity (in scientific theories); Theoretical (epistemic) virtues).

In contrast to foundationalism, coherentism claims that every belief derives some of its justification from other beliefs (see Knowledge and justification, coherence theory of; Probability theory and epistemology; Bosanquet, B.; Bradley, F.H.). All coherentists hold that, like the poles of a tepee, beliefs are mutually reinforcing. Some coherentists, however, assign a special justificatory role to those propositions that are more difficult to dislodge because they provide more support for the other propositions and are more supported by them. The set of these special propositions overlaps the set of basic propositions specified by foundationalism.

There are some objections aimed specifically at foundationalism and others aimed specifically at coherentism. But there is one deep difficulty with both traditional normative accounts. This problem, known as the ‘Gettier Problem’ (after a famous three-page article by Edmund Gettier in 1963), can be stated succinctly as follows (see Gettier problems): suppose that a false belief can be justified (see Fallibilism), and suppose that its justificatory status can be transferred to another proposition through deduction or other principles of inference (see Deductive closure principle). Suppose further that the inferred proposition is true. If these suppositions can be true simultaneously – and that seems to be the case – the inferred proposition would be true, justified (by either foundationalist or coherentist criteria) and believed, but it clearly is not knowledge, since it was inferred from a false proposition. It is a felicitous coincidence that the truth was obtained.

One strategy for addressing the Gettier Problem remains firmly within the normative tradition. It employs the original normative intuition that it is the quality of the reasons that distinguishes knowledge from mere true belief. This is the defeasibility theory of knowledge. There are various defeasibility accounts but, generally, all of them hold that the felicitous coincidence can be avoided if the reasons which justify the belief are such that they cannot be defeated by further truths (see Knowledge, defeasibility theory of).