Internalism and Externalism in Epistemology

by

Mylan Engel

• LAST REVIEWED: 10 November 2022
• LAST MODIFIED: 28 October 2020
• DOI: 10.1093/obo/9780195396577-0414

Introduction

The internalism/externalism distinction in epistemology applies to both theories of justification and theories of knowledge. The distinction is most clearly defined for theories of justification. An internalist theory of epistemic justification is any theory that maintains that epistemic justifiedness is exclusively a function of states internal to the cognizer. Externalism is the denial of internalism. Thus, an externalist theory is any theory that maintains that epistemic justifiedness is at least partly a function of states or factors external to the cognizer, i.e., states or factors outside the cognizer’s ken. There is no unified agreement among internalists as to which internal states are epistemically relevant, and different internalisms emerge based on the subset of internal states deemed relevant. (See Internalism and Justification for details.) Internalists typically maintain that justification is a normative notion in the belief-guiding/regulative sense. Internalists also typically maintain that one can tell whether one is justified in believing p simply by reflecting on one’s internal evidence for p. The central internalist intuition, as highlighted by the New Evil Demon Problem is this: There can be no difference in justification without a difference in epistemically relevant internal states. Externalism is motivated by the intuition that epistemic justification must be conceptually connected to truth such that the conditions that make a belief justified also make it objectively probable. Externalists are also typically motivated by the view that children and animals can form justified beliefs, while failing to satisfy the internalist’s intellectualist requirements for justification. The dominant externalist theory of justification is process reliabilism, a simplified version of which holds that a belief is justified iff it’s produced by a reliable process. There is less canonical agreement when it comes to applying the internalist/externalist distinction to theories of knowledge. In one sense, every plausible epistemology is an externalist theory because every plausible epistemology requires an externalist truth condition and an externalist Gettier-blocking fillip. However, in another widely used sense, “externalist” theories of knowledge are theories that replace the internalist justification condition with either an externalist justification condition or some other externalist constraint (such as a causal or modal constraint); while “internalist” theories of knowledge hold that internalist justification is necessary for knowledge and also typically hold that no other kind of justification is needed for knowledge, though they do incorporate some sort of externalist constraint to handle the Gettier problem.

General Overviews

Some of the best general overviews of the internalism/externalism debate in epistemology appear in the Internet Encyclopedia of Philosophy (IEP) and the Stanford Encyclopedia of Philosophy (SEP), both of which are free, readily available online resources. For those new to the debate, two good places to start are the IEP article Internalism and Externalism in Epistemology and Pappas 2014 (SEP). Another excellent online introduction to the internalist/externalist distinction appears in Steup 2005, the SEP article on epistemology. For excellent overviews of externalist reliabilist epistemologies, see Goldman and Beddor 2015 (SEP) and Reliabilism (IEP), the latter of which also includes discussion of proper-functionalist, virtue-reliabilist, and sensitivity and safety approaches. Hasan and Fumerton 2016 provides an excellent overview of internalist and externalist foundationalist theories of justification. The IEP article on Evidentialism gives a helpful overview of this internalist approach to epistemic justification, while the IEP article on Epistemic Luck provides a comprehensive overview of internalist and externalist attempts (including modal attempts) to block knowledge-destroying veritic luck. It also includes a discussion of how the Gettier problem impacts the possibility of internalistic second-order knowledge. In addition to these online resources, Laurence BonJour provides a very succinct entry on internalism and externalism in the Blackwell Companion to Epistemology (BonJour 2010a) and a more comprehensive overview of the debate in his book Epistemology (BonJour 2010b). Kim 1993 provides an excellent, nuanced system for classifying theories as internalist or externalist. After identifying introspectibility as the proper epistemological criterion of the internal, Kim argues that the internalism/externalism distinction can be drawn along three different dimensions—grounds, adequacy, and the basing relation—and concludes that the degree to which a theory is internalist (externalist) is a function of the number of dimensions along which it is internalist (externalist). Goldberg 2015 argues that the internalism/externalism debate is best understood as a substantive dispute over whether or not epistemically appropriate belief requires mind-world warrant.

• Becker, Kelly. “Reliabilism.” Internet Encyclopedia of Philosophy.

  A comprehensive overview of various externalistic reliabilist epistemologies, including process reliabilism, proper functionalism, virtue reliabilism, sensitivity-based truth-tracking accounts of knowledge, and safety-based anti-luck epistemologies.

• BonJour, Laurence. “Externalism/Internalism.” In A Companion to Epistemology. 2d ed. Edited by Jonathan Dancy, Ernest Sosa, and Matthias Steup, 364–368. Malden, MA: Blackwell, 2010a.

  A very concise overview of the internalism/externalism distinction with respect to epistemic justification. Also contains a brief discussion of internalism and externalism with respect to knowledge and with respect to the content of thought.

• BonJour, Laurence. “Internalism and Externalism.” In his Epistemology: Classic Problems and Contemporary Responses. 2d ed. By Laurence BonJour, 203–219. Lanham, MD: Rowman and Littlefield, 2010b.

  A highly accessible overview of the internalist/externalist debate with respect to epistemic justification. Provides an extremely clear explication of the main reasons for and against each approach. This chapter is well suited for introducing undergraduates to the key issues involved in the internalist/externalist debate.

• Engel, Mylan, Jr. “Epistemic Luck.” Internet Encyclopedia of Philosophy.

  A comprehensive overview of internalist and externalist attempts to block knowledge-destroying epistemic luck, including modal attempts to rule out veritic luck. Concludes with a discussion of how the Gettier problem impacts the possibility of internalistic second-order knowledge (i.e., the Gettier problem’s impact on the possibility of internalistically knowing that one internalistically knows that p).

• Goldberg, Sanford. “What Is the Subject-Matter of the Theory of Epistemic Justification?” In Epistemic Evaluation: Purposeful Epistemology. Edited by David Henderson and John Greco, 205–223. Oxford: Oxford University Press, 2015.

  Proposes that the theory of epistemic justification concerns the conditions that make belief epistemically proper. Contends the internalism/externalism debate is a substantive dispute over whether or not epistemically appropriate belief requires mind-world (MW) warrant, where MW warrant is understood in terms that make ineliminable appeal to a relation between mind and world. Argues that internalists maintain that epistemic propriety is independent of MW warrant, while externalists contend that epistemic propriety requires MW warrant.

• Goldman, Alvin, and Bob Beddor. “Reliabilist Epistemology.” The Stanford Encyclopedia of Philosophy. Edited by Edward N. Zalta. Stanford, CA: Stanford University, 2015.

  A comprehensive overview of reliabilist approaches to justification and knowledge.

• Hasan, Ali, and Richard Fumerton. “Foundationalist Theories of Epistemic Justification.” The Stanford Encyclopedia of Philosophy. Edited by Edward N. Zalta. Stanford, CA: Stanford University, 2016.

  A comprehensive overview of internalist and externalist versions of foundationalism.

• Kim, Kihyeon. “Internalism and Externalism in Epistemology.” American Philosophical Quarterly 30.4 (1993): 303–316.

  Defines “internality” in terms of introspectibility. Argues that the internalism/externalism distinction can be drawn along three different dimensions—grounds, adequacy, and the basing relation. A theory of justification can be internalist with respect to one dimension (say, grounds) and externalist with respect to another (say, adequacy). The degree to which a theory is internalist (externalist) is a function of the number of dimensions along which it is internalist (externalist).

• Mittag, Daniel. “Evidentialism.” Internet Encyclopedia of Philosophy.

  A relatively brief introduction to the evidentialist approach to epistemic justification and to the internalistic nature of having or possessing evidence that is central to the theory.

• Pappas, George. “Internalist vs. Externalist Conceptions of Epistemic Justification.” The Stanford Encyclopedia of Philosophy. Edited by Edward N. Zalta. Stanford, CA: Stanford University, 2014.

  Examines internalist and externalist conceptions of knowledge and justification. Focuses primarily on internalism and externalism as applied justification. Discusses three forms of justification internalism: access internalism, mentalism, and deontological justification. Explores reasons for and against each of these forms of justification internalism.

• Posten, Ted. “Internalism and Externalism in Epistemology.” Internet Encyclopedia of Philosophy.

  Provides a clear comprehensive overview of the internalism/externalism debate particularly as it applies to theories of epistemic justification. Identifies the primary reasons for internalism and the primary reasons for externalism, and explores the significance of the internalism/externalism debate for contemporary epistemology.

• Steup, Matthias. “Epistemology.” Stanford Encyclopedia of Philosophy. Edited by Edward N. Zalta. Stanford, CA: Stanford University, 2005.

  Contains an extremely accessible, helpful overview of deontological and non-deontological approaches to justification and the primary motivations for each approach. Examines access internalism and mentalist internalism with respect to justification. Briefly considers the primary motivations for justification internalism (justification requires evidence and evidence must be internal) and justification externalism (non-human animals possess justified belief, and justification must objectively probabilify belief).