Keith Lehrer

1. Introduction

Keith Lehrer (1936–2020) was an American analytic philosopher whose work is widely regarded as a central reference point in late twentieth‑century epistemology. He is best known for developing a sophisticated form of coherentism combined with epistemic internalism, most fully presented in his monograph Knowledge (1981) and his influential article “Justification, Truth, and Coherence” (1979). Within this framework, justification depends on the coherence of what a person accepts upon reflective scrutiny, and knowledge is analyzed as undefeated justified true belief.

Lehrer’s approach became a prominent alternative to both classical foundationalism and externalist reliabilism, shaping the post‑Gettier debate about the analysis of knowledge. Proponents of his view emphasize its careful treatment of defeaters, its insistence on the subject’s reflective perspective, and its attempt to connect coherence with truth. Critics have questioned whether coherence can provide an adequate link to truth, and whether internalist conditions can be reconciled with naturalistic accounts of cognition.

Beyond core epistemology, Lehrer extended his ideas to autonomy, self‑trust, and preference, influencing discussions in ethics and decision theory. His analyses of consensus and testimony contributed to emerging work in social epistemology. At the same time, he was an important expositor and teacher of analytic philosophy, co‑authoring textbooks that helped standardize how epistemology is presented in Anglophone curricula.

This entry surveys Lehrer’s life and historical setting, traces the development of his thought, outlines his major works, and examines his contributions to epistemology, moral psychology, decision theory, and social philosophy, as well as subsequent critical responses and interpretations.

2. Life and Historical Context

Lehrer was born on 10 January 1936 in Evanston, Illinois, and pursued his philosophical training in the milieu of mid‑twentieth‑century American analytic philosophy. Completing his PhD at Brown University in 1968 under Roderick Chisholm, he was initially formed within a rigorous, intuition‑driven, largely foundationalist epistemological tradition. This Chisholmian background set the stage for Lehrer's later engagement with, and eventual departure from, foundationalism.

His long tenure at the University of Rochester, beginning in 1964, coincided with major shifts in analytic philosophy. The Gettier problem (1963) had disrupted the traditional “justified true belief” analysis of knowledge, and debates about evidence, justification, and skepticism were rapidly intensifying. Lehrer’s early papers in the 1960s and 1970s emerged directly from this ferment, positioning him among those attempting to reconstruct a viable theory of knowledge in the wake of Gettier.

Historically, Lehrer's work spans the transition from mid‑century internalist, a priori epistemology to later, more naturalistic and externalist approaches. He defended a refined internalism precisely as reliabilism, Nozick’s tracking theory, and other externalist accounts were gaining traction. His move to the University of Arizona later in his career placed him in a department known for decision theory, ethics, and philosophy of mind, contexts that informed his work on autonomy and preference.

Lehrer died on 13 January 2020 in Tucson, Arizona, from complications related to Parkinson’s disease. By that time, his writings had become standard reference points in discussions of coherence, justification, and the role of the subject in knowledge.

Chronological overview

3. Intellectual Development

Lehrer’s intellectual trajectory is often described in terms of a shift from Chisholmian foundationalism to a distinctive, systematically elaborated coherentism, followed by an extension of these epistemic themes into broader issues of rational agency.

From Chisholmian foundations to coherence

In his formative years at Brown University, Lehrer absorbed Chisholm’s internalist methodology: reliance on epistemic intuitions, careful analysis of evidence, and the search for basic beliefs immune to radical doubt. Early work reflects this training, even as Lehrer became increasingly skeptical of the viability of indubitable foundations. Scholars sometimes interpret this stage as one of “critical allegiance,” in which Lehrer accepted Chisholm’s internalism but gradually questioned its foundationalist structure.

Early epistemology and the Gettier context

In the 1960s and 1970s, while at Rochester, Lehrer engaged directly with the Gettier problem, skeptical scenarios, and the structure of justification. He began to explore the idea that justification might be a matter not of resting on secure foundations but of the coherence of an entire belief system, especially under conditions of critical reflection and error correction. These explorations led to the formulation of key notions such as acceptance and personal justification.

Systematic coherentism and beyond

With “Justification, Truth, and Coherence” (1979) and Knowledge (1981), Lehrer articulated a mature theory: knowledge as undefeated justified true belief within a coherent set of acceptances. This stage is marked by detailed accounts of defeaters, the role of truth, and the first‑person perspective. In the late 1980s and 1990s, Lehrer's interests broadened. In Metamind (1990) and Self‑Trust (1997), he developed an account of self‑evaluation, autonomy, and preference, applying his coherence‑based framework to decision theory and moral psychology.

Later writings revisit earlier epistemological themes while integrating them with questions about free will, responsibility, and the self, illustrating a continuing effort to connect theories of knowledge with a comprehensive picture of rational agency.

4. Major Works

Lehrer’s main writings span technical epistemology, introductions to theory of knowledge, and interdisciplinary work linking epistemology to autonomy and decision theory.

Principal monographs and books

Influential articles

Among his articles, “Justification, Truth, and Coherence” (Synthese, 1979) is especially prominent. It offers a concise, technically nuanced defense of coherentism and introduces components that are central in Knowledge, including:

• The distinction between belief and acceptance
• The idea of undefeated justification
• The attempt to connect coherence with truth while preserving internalism

Lehrer also co‑authored and contributed to various collections and essays on autonomy, preference, and decision theory, where he elaborated the notion of preference autonomy and its relation to rational choice. Commentators often group these writings together as a second phase of major contributions, complementing the earlier epistemological work.

Primary‑source discussions of his views typically draw on these core texts, which together provide an integrated picture: from a theory of knowledge and justification to a broader account of rational, autonomous agency.

5. Core Ideas in Epistemology

Lehrer’s epistemology centers on a distinctive combination of coherentism, internalism, and a refined version of the traditional analysis of knowledge.

Undefeated justified true belief

Lehrer maintains a modified “JTB” structure: knowledge is true belief that is justified and undefeated. A belief is justified when it coheres with what the subject accepts upon critical reflection. It is undefeated when no defeater—no accessible consideration that would undercut its justification—remains unaddressed. He summarizes this view in Knowledge:

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Knowledge is not merely true belief but undefeated justified true belief, where the justification coheres with the rest of what the person accepts.

— Keith Lehrer, Knowledge

Proponents see this as preserving the intuitive appeal of JTB while handling Gettier‑style counterexamples through the notion of defeat. Critics argue that the account may still allow problematic cases or that “undefeated” status is difficult to specify non‑circularly.

Coherentism and acceptance

Lehrer’s coherentism holds that justification is a property of entire systems of acceptances rather than of beliefs grounded in indubitable foundations. Acceptance is a reflective stance: one is prepared to use the content in reasoning and deliberation. Justification depends on the mutual support and integration of what is accepted, especially after critical reflection and attempted error‑correction.

Supporters claim this captures the holistic nature of actual reasoning and fits internalist constraints, since the relevant relations are, in principle, accessible to the subject. Opponents, drawing on alternative epistemologies, question whether coherence among beliefs is sufficiently connected to truth, and whether highly coherent but systematically mistaken systems could still appear justified on Lehrer's account.

Internalism and the subject’s point of view

Lehrer’s internalism insists that the factors that make a belief justified must be available to the subject’s consciousness or reflection. He opposes purely externalist theories, such as reliabilism, which ground knowledge in causal or statistical relations that need not be accessible. For Lehrer, rational agents assess potential defeaters, reflect on the coherence of their acceptances, and thereby achieve epistemic entitlement.

Debate continues over whether this internalist requirement is compatible with naturalistic explanations of cognition and with the role of unconscious processes, with some commentators defending hybrid views that incorporate elements of Lehrer's internalism into broader frameworks.

6. Autonomy, Self‑Trust, and Decision Theory

Lehrer extends his epistemological framework to an account of personal autonomy, self‑trust, and preference that intersects with ethics and decision theory.

Self‑trust and rational agency

In Self‑Trust: A Study of Reason, Knowledge, and Autonomy, Lehrer argues that rational agents must, under certain conditions, trust their own cognitive faculties. Self‑trust is not blind faith; it is a reflective endorsement that survives scrutiny:

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Self‑trust is not blind faith in our faculties but the rational acceptance of their deliverances when no undefeated reason for doubt remains.

— Keith Lehrer, Self‑Trust

According to Lehrer, without such self‑trust, agents would be trapped in skepticism and unable to form stable, justified beliefs. Proponents see this as a natural extension of his coherentism: just as justification arises from coherence among acceptances, rational agency requires coherent self‑acceptance of one’s own methods of belief‑formation. Critics ask whether this introduces a kind of circularity—trusting one’s faculties because those same faculties recommend self‑trust—or whether it can be reconstructed as a “default entitlement” view.

Preference autonomy and decision theory

Lehrer also develops the idea of preference autonomy, applying coherence and reflective endorsement to preferences and choices. An agent’s decisions are autonomous, on this view, when their preferences cohere with what they reflectively accept about themselves—their values, long‑term plans, and self‑conception.

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Autonomy involves the evaluation and endorsement of our own preferences; an autonomous agent is one whose preferences cohere with what he reflectively accepts about himself.

— Keith Lehrer, essays on autonomy and preference

In decision‑theoretic terms, some commentators interpret Lehrer as proposing that rational choice is not grounded solely in revealed preference or utility maximization, but in a structure of preferences that is coherent, stable under reflection, and undefeated by information about the agent’s deeper commitments. This has been contrasted with more behavioristic or strictly formal models of rational choice, with debate focusing on how to model “reflective endorsement” within decision theory and whether autonomy‑conditions are normative constraints or descriptive features of actual decision making.

7. Methodology and Style

Lehrer’s philosophical method combines traditional analytic techniques with a distinctive emphasis on the first‑person perspective and reflective endorsement.

Internalist, first‑person methodology

Methodologically, Lehrer works from the standpoint of the subject’s point of view. He analyzes what agents can justifiably accept given their evidence and capacity for reflection. This involves:

• Careful use of thought experiments (e.g., Gettier‑type cases) to probe intuitions about knowledge and justification.
• Systematic attention to defeaters and how they affect the rational status of beliefs.
• A reliance on conceptual analysis of epistemic notions (knowledge, justification, acceptance) framed in accessible prose.

Supporters regard this approach as preserving the normative dimension of epistemology: it explains what one ought to accept given one’s situation. Critics, especially from externalist or naturalistic perspectives, question whether such first‑person analysis can be reconciled with empirical cognitive science or whether it overemphasizes reflective access.

Stylistic features

Lehrer’s style is generally characterized as:

• Clear and didactic: especially in Knowledge and Theory of Knowledge, where arguments are laid out stepwise, often with summaries and explicit definitions.
• Systematic: he develops interconnected notions—acceptance, coherence, self‑trust—across multiple works, aiming for an integrated theory.
• Moderately formalized: while he occasionally uses diagrams or semi‑formal notation to represent coherence relations, he does not rely heavily on symbolic logic or probability theory.

In comparison with contemporaries, some see Lehrer as closer to Chisholm in his use of ordinary language and intuitive cases, but closer to coherentists like BonJour in the structural holism of his theory. Debates about his work often turn on how far such a method can be pushed without additional formal or empirical constraints.

8. Impact on Analytic Philosophy

Lehrer’s impact on analytic philosophy is most pronounced in epistemology, but it also extends to methodology, moral psychology, and decision theory.

Reshaping post‑Gettier epistemology

Lehrer’s coherentist account became a central alternative in post‑Gettier debates. Along with other coherentists, he helped shift attention from foundational beliefs to the structure of a subject’s entire belief system. His detailed treatment of defeaters and undefeated justification influenced later discussions of defeat, both in epistemology and in formal epistemic logic.

Many survey texts and anthologies present Lehrer's theory alongside foundationalism, reliabilism, and tracking theories, treating it as one of the standard positions with which any comprehensive epistemology must engage. Some proponents see his work as helping to keep internalism alive during a period dominated by externalist accounts.

Influence on key debates

Lehrer’s ideas have been taken up or discussed in several ongoing debates:

In moral psychology and decision theory, his ideas on preference autonomy and reflective endorsement have been compared with other accounts of autonomy (e.g., hierarchical or procedural theories). Some philosophers in these areas use Lehrer's framework as a contrasting case when developing their own models of rational agency.

Overall, while not every subsequent epistemologist identifies as a coherentist, Lehrer's systematic articulation of coherentist internalism has become a standard reference point, shaping how core options in analytic epistemology are framed and taught.

9. Influence on Social Epistemology and Ethics

Lehrer’s work has had notable implications for social epistemology—the study of knowledge in social contexts—and for ethical theory, especially regarding autonomy and responsibility.

Social epistemology: testimony, consensus, and information

From within his internalist framework, Lehrer analyzes how information from others—testimony, expert opinion, and consensus—can contribute to justified belief. He holds that such social inputs become justifiers when they are coherently integrated into an agent’s system of acceptances and when potential defeaters (e.g., evidence of bias or unreliability) are addressed.

This has influenced later discussions of:

• How individuals should weigh expert testimony against their own evidence.
• The epistemic role of consensus in science and politics.
• Conditions under which disagreement should lead to revision or suspension of belief.

Some social epistemologists regard Lehrer’s approach as an early, systematic attempt to reconcile individual autonomy in belief‑formation with genuine epistemic dependence on others. Critics argue that his strong internalist demands may understate the extent to which agents reasonably rely on opaque, complex social processes they cannot fully assess.

Ethics: autonomy, responsibility, and self‑evaluation

Lehrer’s conception of preference autonomy and self‑trust has drawn attention in ethical debates about:

• What it means for a person to act autonomously.
• How self‑knowledge and coherent self‑evaluation relate to responsibility.
• Whether problematic or adaptive preferences (e.g., shaped by oppression) can count as autonomous.

Ethical theorists have compared Lehrer's coherence‑based account with hierarchical models of autonomy (such as those of Frankfurt or Dworkin) and with procedural or relational approaches. Some see his stress on reflective endorsement and coherence as providing useful criteria for distinguishing between merely habitual behavior and genuinely autonomous choice. Others question whether coherence with one’s self‑conception is sufficient, especially when that self‑conception has been shaped under unjust conditions.

Despite such disagreements, Lehrer's work continues to serve as a touchstone for attempts to integrate epistemic and ethical dimensions of agency, highlighting the role of reflection, coherence, and self‑trust in both knowing and acting.

10. Legacy and Historical Significance

Lehrer’s legacy in philosophy is closely tied to his role in articulating and defending a detailed, internalist coherentist theory of knowledge at a time when many epistemologists were moving toward externalism and naturalism.

Historically, his monograph Knowledge and the article “Justification, Truth, and Coherence” helped define the landscape of post‑Gettier epistemology. These works continue to be cited in discussions of coherence theories, defeaters, and the structure of justification. Many contemporary overviews of epistemology treat Lehrer's position as one of the canonical options, alongside foundationalist and reliabilist accounts.

From a pedagogical standpoint, his textbooks and expository writings have had lasting influence on how epistemology is taught, especially in Anglophone contexts. Generations of students have encountered issues about knowledge, skepticism, and justification through frameworks that explicitly engage with Lehrer's distinctions between belief and acceptance, justification and undefeated justification.

In broader historical perspective, some commentators interpret Lehrer as a key transitional figure: rooted in mid‑century, Chisholm‑style internalism, yet responsive to newer concerns about social information, autonomy, and decision theory. His later work on self‑trust and preference autonomy has contributed to ongoing efforts to connect epistemology with ethics, rational choice theory, and theories of the self.

Assessments of Lehrer's ultimate place in the philosophical canon differ. Some view his coherentism as a cornerstone of internalist epistemology; others see it mainly as an instructive foil for alternative theories. Nonetheless, there is wide agreement that his systematic exploration of coherence, defeat, and reflective endorsement significantly shaped late twentieth‑century analytic philosophy and remains essential for understanding the development of contemporary epistemology.