Naturalized Epistemology

Overview

Naturalized epistemology is a radical proposal. It says that epistemology — the study of knowledge, justification, and rational belief — should not be a purely philosophical enterprise conducted from the armchair. Instead, it should be continuous with empirical science. The questions that traditional epistemologists asked with thought experiments and conceptual analysis should be investigated with the tools of psychology, neuroscience, cognitive science, and evolutionary biology.

The proposal is most closely associated with W. V. O. Quine, whose 1969 essay "Epistemology Naturalized" gave the movement its name and its manifesto. Quine argued that the traditional Cartesian project — finding an indubitable foundation for knowledge through pure reason — had failed. The Humean project — justifying induction through empirical evidence — had also failed. What remained was to treat epistemology as a chapter of empirical psychology: to study how human beings actually construct their picture of the world from sensory input.

This was controversial. Critics charged that Quine had not reformed epistemology but abolished it. If epistemology becomes psychology, what happens to the normative questions — questions about what we ought to believe, what counts as good reasoning, what distinguishes knowledge from mere opinion? The debate over whether naturalized epistemology can preserve normativity remains one of the central discussions in the field.

Core Principles

Naturalized epistemology is less a single theory than a family of approaches, but several commitments are widely shared.

Continuity with Science

The defining commitment is that epistemology is continuous with natural science. There is no sharp boundary between philosophical questions about knowledge and scientific questions about cognition. The methods of epistemology — to the extent that it has distinctive methods — are the methods of empirical science: observation, experimentation, theory construction, and hypothesis testing.

Rejection of First Philosophy

Naturalized epistemology rejects what Quine called "first philosophy" — the idea that epistemology can stand outside science and provide a foundation for it. There is no external standpoint from which to evaluate the credentials of science as a whole. We must evaluate scientific theories from within science itself, using the best available empirical methods. This is a naturalistic, fallibilist approach: all claims to knowledge are revisable in light of further evidence.

Empirical Study of Belief Formation

A central task of naturalized epistemology is to study how human beings actually form beliefs. How does sensory stimulation give rise to perceptual beliefs? How reliable are our cognitive mechanisms? What biases and heuristics shape our reasoning? These questions are investigated through the methods of cognitive psychology, neuroscience, and evolutionary biology. The findings of these sciences are directly relevant to epistemological questions.

Normativity and Descriptive Adequacy

The most contentious issue is how to preserve the normative dimension of epistemology. Traditional epistemology tells us what we ought to believe; a purely descriptive science tells us what we do believe. Naturalized epistemologists have offered various responses. Some argue that normativity can be reduced to facts about reliable belief-forming processes. Others argue that normativity is preserved through the concept of proper functioning — cognitive systems have norms built into their design. Still others embrace a thoroughgoing descriptivism, arguing that epistemology should give up normative ambitions entirely.

Key Thinkers

W. V. O. Quine (1908–2000)

Quine is the founding figure of naturalized epistemology. In "Epistemology Naturalized" (1969), he argued that the traditional foundationalist project had collapsed and that epistemology should be absorbed into empirical psychology. Quine's vision was radical: he saw epistemology as investigating "a relation between the meager input and the torrential output" of human cognition. His naturalism was part of a broader philosophical program that included his holism, his rejection of the analytic-synthetic distinction, and his commitment to physicalism.

Alvin Goldman (1938–)

Goldman developed a version of naturalized epistemology that retained normative ambitions. His reliabilism — the view that justified beliefs are those produced by reliable cognitive processes — is inherently naturalistic, because reliability is an empirical property that can be investigated by science. Goldman's later work in social epistemology extended the naturalistic approach to institutions and practices, evaluating them by their tendency to produce true beliefs.

Hilary Kornblith (1950–)

Kornblith has been one of the most thoughtful defenders and developers of naturalized epistemology. In Knowledge and Its Place in Nature (2002), he argues that knowledge is a natural kind — a real phenomenon studied by cognitive science — and that epistemology should investigate this natural kind rather than analyzing concepts. Kornblith's approach is more metaphysical than Quine's, but shares the commitment to continuity with science.

Fred Dretske (1932–2013)

Dretske's work on information theory and knowledge provided important resources for naturalized epistemology. His idea that knowledge involves the receipt of information — a notion that can be made precise in information-theoretic terms — offered a way to naturalize the concept of knowledge without reducing it to mere belief. Dretske's approach influenced both reliabilism and the broader naturalistic turn.

Historical Development

The roots of naturalized epistemology extend back to the empiricist tradition. Hume's ambition to apply the "experimental method of reasoning to moral subjects" anticipated the naturalistic approach. The American pragmatists — Peirce, James, and Dewey — were naturalists in spirit, treating inquiry as a biological and social process rather than a purely rational one.

But the explicit call for naturalization came from Quine. His 1969 essay was both a diagnosis and a prescription. He diagnosed the failure of two traditional epistemological projects: the Cartesian project of deducing science from sense data, and the Humean project of rationally justifying induction. Since both had failed, Quine argued, epistemology should abandon its foundational ambitions and become part of psychology.

The proposal provoked intense debate. Critics like Jaegwon Kim argued that Quine had replaced epistemology with something else entirely — that a purely descriptive psychology could not address the normative questions that make epistemology a distinct philosophical discipline. Kim's challenge forced naturalized epistemologists to clarify how they intended to preserve normativity.

Through the 1980s and 1990s, various strategies emerged. Goldman's reliabilism provided one approach: by defining justification in terms of reliable processes, normativity is preserved but made empirically tractable. Kornblith's approach treated knowledge as a natural kind, arguing that epistemology investigates a real phenomenon rather than a concept. Others, like Patricia Churchland, pushed toward a more radical neurophilosophy, arguing that neuroscience would eventually replace traditional epistemology.

The rise of cognitive science and evolutionary psychology in the 1990s and 2000s provided new resources. Studies of heuristics and biases, perceptual mechanisms, and the evolution of cognition all fed into naturalized epistemological projects. The field also expanded to encompass social and institutional dimensions, with Goldman and others applying naturalistic methods to testimony, expert opinion, and information technology.

Contemporary Relevance

Naturalized epistemology has shaped both philosophy and the sciences of cognition.

In philosophy, the naturalistic turn has become the default approach for many epistemologists. Even philosophers who do not identify as naturalists increasingly draw on empirical findings about perception, memory, reasoning, and bias. The boundary between philosophy of mind, cognitive science, and epistemology has become increasingly porous.

In psychology and cognitive science, the philosophical framework of naturalized epistemology provides a broader context for empirical research. Studies of reasoning errors, perceptual illusions, and memory distortions are not just isolated findings — they contribute to our understanding of the reliability of human cognition, which is a fundamentally epistemological question.

In the study of expertise and expert judgment, naturalized epistemology provides tools for evaluating the reliability of different methods. The recognition-primed decision model, studies of expert intuition, and research on calibration all have epistemological implications that naturalized epistemology helps to articulate.

In artificial intelligence and machine learning, questions about the reliability of belief-forming systems (whether human or artificial) are naturally framed in the terms of naturalized epistemology. How do we evaluate whether a learning algorithm produces reliable beliefs? What norms should govern the design of AI systems that form beliefs about the world? These are both empirical and philosophical questions.

Sources

• Quine, W. V. O. "Epistemology Naturalized." In Ontological Relativity and Other Essays. New York: Columbia University Press, 1969.
• Kornblith, Hilary. Knowledge and Its Place in Nature. Oxford: Oxford University Press, 2002.
• Goldman, Alvin I. Epistemology and Cognition. Cambridge, MA: Harvard University Press, 1986.
• Kim, Jaegwon. "What Is 'Naturalized Epistemology'?" Philosophical Perspectives 2 (1988): 381–405.
• "Naturalized Epistemology." Stanford Encyclopedia of Philosophy, ed. Edward N. Zalta. https://plato.stanford.edu/entries/epistemology-naturalized/
• Dretske, Fred. Knowledge and the Flow of Information. Cambridge, MA: MIT Press, 1981.
• Kornblith, Hilary, ed. Naturalizing Epistemology. 2nd ed. Cambridge, MA: MIT Press, 1994.