Frank Cameron Jackson

1. Introduction

Frank Cameron Jackson (b. 1943) is an Australian analytic philosopher whose work has been central to late twentieth- and early twenty-first-century debates in philosophy of mind, metaphysics, metaethics, and philosophical methodology. He is best known for formulating the knowledge argument against physicalism through the “Mary the colour scientist” thought experiment, and for later revising his position to defend a sophisticated form of physicalism. This combination of bold argument and subsequent retraction has made his work a focal point for discussion about qualia, consciousness, and the limits of scientific explanation.

Jackson’s philosophical contributions extend well beyond philosophy of mind. In metaphysics, he has developed influential accounts of properties, possible worlds, and the relation between higher-level and physical descriptions. In ethics, he has defended a naturalistically respectable moral realism via analytic moral functionalism, according to which moral properties are higher-order roles realized by natural properties.

Methodologically, Jackson has been a prominent defender of conceptual analysis as a central, though fallible, a priori tool, arguing that careful reflection on our concepts—constrained by empirical science—yields substantive metaphysical and ethical insight. His work thus occupies a distinctive position at the intersection of armchair reflection and scientific theorizing, and has helped shape contemporary analytic philosophy’s self-understanding.

The following sections examine Jackson’s life and context, the development of his views, and his major contributions to philosophy of mind, metaphysics, ethics, and philosophical method, as well as his broader impact and historical significance within the analytic tradition.

2. Life and Historical Context

2.1 Biographical Sketch

Jackson was born in 1943 in Australia to philosophers C. B. Jackson and Joan Jackson, a background that reportedly immersed him early in analytic discussion. He studied philosophy, mathematics, and related disciplines at the University of Melbourne and later the University of Adelaide in the 1960s, during the consolidation of the Australasian analytic tradition. His academic career began in the late 1960s and early 1970s, with appointments including La Trobe University, the Australian National University (ANU), and later visiting and joint positions at institutions such as Princeton University.

2.2 Historical and Intellectual Setting

Jackson’s formative years coincided with a period in which analytic philosophy was increasingly shaped by formal logic, engagement with the sciences, and the legacy of logical empiricism. In Australia, figures such as J. J. C. Smart and D. M. Armstrong were developing influential versions of materialism, theories of mind, and naturalistic metaphysics. Jackson’s early work emerged against this backdrop of scientifically informed realism and a strong focus on clarity and argument.

The broader international context included the rise of functionalism in philosophy of mind, debates over behaviorism and identity theory, and renewed interest in possible worlds semantics and counterfactuals. Jackson engaged directly with these currents, contributing to the analysis of conditionals, perception, and consciousness. His 1982 paper “Epiphenomenal Qualia” entered debates already animated by Thomas Nagel’s “What is it like to be a bat?” and Hilary Putnam’s functionalism, and it quickly became a canonical challenge to physicalist theories.

Later, as naturalistic approaches and cognitive science gained prominence, Jackson’s shift toward physicalism and his defense of conceptual analysis positioned him within evolving discussions about how a priori methods could coexist with empirically driven philosophy.

3. Intellectual Development

3.1 Formative Phase: Perception and Representation

Jackson’s early work, culminating in Perception: A Representative Theory (1977), focused on perception and representational content. He argued for a representative theory rather than naïve realism, analyzing how perceptual experience presents the world. This phase exhibits a careful, logically driven style that would characterize his later work and prepared the ground for his views on mental content and qualia.

3.2 Anti-Physicalist Phase: The Knowledge Argument

In the late 1970s and 1980s, Jackson developed the knowledge argument against physicalism. In “Epiphenomenal Qualia” (1982), he proposed that a subject like Mary, who knows all the physical facts about colour but has never seen it, learns something new—what it is like to see red—upon leaving her black-and-white environment. Jackson used this to defend a form of property dualism and epiphenomenalism: qualia were taken to be non-physical properties caused by, but not causing, physical states.

This period made Jackson internationally prominent and firmly associated him with anti-physicalist arguments about consciousness.

3.3 Systematic Expansion: Metaphysics and Ethics

From the late 1980s through the 1990s, Jackson broadened his focus. In work culminating in From Metaphysics to Ethics (1998), he developed connected views on properties, possible worlds, and moral realism, tied together by a defense of conceptual analysis. He argued that careful analysis of our concepts, in tandem with empirical science, yields substantive metaphysical and ethical theses, including his analytic moral functionalism.

3.4 Physicalist Turn and Methodological Refinement

In the early 2000s, Jackson famously recanted his earlier anti-physicalism, notably in pieces such as “Mind and Illusion” (2002). He came to interpret the Mary case as revealing different modes of presentation of the same physical facts, rather than non-physical properties. This physicalist turn did not abandon his earlier emphasis on conceptual analysis but reoriented it: the task became to explain why anti-physicalist intuitions are compelling while still maintaining that the world is wholly physical. Subsequent work further refined his positions on conditionals, representation, and the nature of the a priori.

4. Major Works and Key Publications

4.1 Overview of Central Works

4.2 Perception: A Representative Theory (1977)

This monograph articulates a sophisticated representative theory of perception, defending the view that perceptual experience represents the world rather than putting us in direct contact with external objects. It engages with sense-data theories and the nature of perceptual content, laying foundations for Jackson’s later interest in mental representation and experience.

4.3 “Epiphenomenal Qualia” (1982)

This article introduced the Mary the colour scientist thought experiment and the modern form of the knowledge argument. It has been widely anthologized and remains one of the most cited pieces in philosophy of mind. Jackson there endorses property dualism and argues that qualia are epiphenomenal.

4.4 Conditionals (1987)

In Conditionals, Jackson offers a systematic treatment of indicative and counterfactual conditionals, drawing on possible worlds semantics and probabilistic considerations. The work contributed to debates about the semantics, pragmatics, and logic of conditional sentences and remains a reference point in the literature.

4.5 From Metaphysics to Ethics (1998)

This book synthesizes Jackson’s views across metaphysics, metaethics, and methodology. It presents his defense of conceptual analysis, a version of physicalism grounded in properties and possible worlds, and his influential analytic moral functionalism. It is often regarded as his most systematic statement of his philosophical outlook of the 1990s.

5. Core Ideas in Philosophy of Mind

5.1 The Knowledge Argument and Mary

Jackson’s most famous contribution to philosophy of mind is the knowledge argument against physicalism, developed in “Epiphenomenal Qualia.” The thought experiment of Mary the colour scientist is intended to show that complete physical knowledge does not exhaust all knowledge.

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“It seems, therefore, that one can have all the physical information without having all the information there is to have.”
— Frank Jackson, “Epiphenomenal Qualia” (1982)

Mary, confined to a black-and-white environment but possessing all physical information about colour vision, appears to learn something new when she first sees red: what it is like to have that experience. Jackson initially took this to show that there are non-physical qualia and that physicalism is false.

5.2 Qualia and Epiphenomenalism

During his anti-physicalist phase, Jackson held that qualitative properties of experience—qualia—are non-physical and epiphenomenal. They are caused by brain states but do not themselves cause physical events. Supporters of this reading emphasize his attempt to preserve the reality of conscious experience without altering physical science. Critics argued that epiphenomenalism is implausible, especially regarding our reports and beliefs about experience.

5.3 The Physicalist Reinterpretation

In the early 2000s, Jackson adopted a physicalist stance. He came to view the Mary case as demonstrating only a difference in modes of presentation: Mary gains a new way of knowing the same physical facts, not access to new non-physical facts. On this view, experiential knowledge is a kind of acquaintance or ability knowledge grounded in physical states.

Proponents of this reinterpretation hold that it preserves the intuition that Mary learns something while maintaining physicalism. Opponents contend that the intuitive force of the knowledge argument is better captured by positing non-physical facts or properties, or by rejecting physicalism altogether.

5.4 Broader Mind-Related Themes

Jackson’s work on mind also includes analyses of mental representation, the relation between folk psychological concepts and scientific descriptions, and the status of a priori knowledge about mental states. Across these discussions, he ties questions about consciousness to issues about language, concepts, and the structure of explanation, often seeking to reconcile common-sense mental discourse with a physicalist ontology.

6. Metaphysics, Properties, and Physicalism

6.1 Properties and Possible Worlds

Jackson’s metaphysics centers on properties and possible worlds as key tools for understanding reality. He typically treats possible worlds in a broadly modal realist-friendly or ersatz form, as structured ways things could be, useful for analyzing modality, counterfactuals, and higher-level properties. Properties are often understood as entities that can be instantiated across possible worlds, enabling cross-world comparisons and reductionist strategies.

His work uses these notions to articulate how higher-level properties—mental, moral, and others—can be realized by, or identified with, more basic physical properties without simple linguistic reduction.

6.2 From Anti-Physicalism to Physicalism

Jackson initially opposed physicalism about the mind, as reflected in his acceptance of non-physical qualia. In From Metaphysics to Ethics, however, and especially in later essays, he defends a sophisticated physicalism according to which:

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“The world is as described by the true and complete physics, but that does not mean that all true and complete descriptions of the world are in the language of physics.”
— Paraphrasing Jackson, From Metaphysics to Ethics (1998)

On this view, all facts are ultimately fixed by physical facts, but there are many legitimate, irreducible-sounding ways of describing those facts—using mental, moral, or everyday vocabulary.

6.3 Supervenience, Realization, and Higher-Level Facts

Jackson employs notions of supervenience and realization to explain how higher-level properties depend on but are not simply identical in description to physical properties. Higher-level facts supervene on the physical: no difference at the higher level without some physical difference. Many philosophers regard this as a common strategy among non-reductive or “austere” physicalists.

Supporters see Jackson’s account as a precise articulation of how physicalism can respect multiple legitimate vocabularies. Critics argue that supervenience and realization may not suffice for a robust explanation of mental or moral phenomena, or that Jackson’s framework either collapses into reductionism or leaves unexplained why higher-level properties have the significance they do.

6.4 Metaphysical Modesty

Jackson often characterizes his metaphysics as modest, aiming not at an ultimate ontology beyond science but at clarifying how our various discourses—scientific, moral, psychological—fit together. This stance has been both praised as a disciplined, scientifically sensitive metaphysics and questioned by those who seek a more robust, independent metaphysical picture or who doubt the reliability of conceptual analysis as a guide to metaphysical structure.

7. Ethics, Moral Functionalism, and Objectivity

7.1 Analytic Moral Functionalism

In metaethics, Jackson is best known for his analytic moral functionalism, presented systematically in From Metaphysics to Ethics. On this view, moral properties are higher-order properties defined by the roles they play in our moral practices—roughly, by their connections to reasons, desires, emotions, and social regulation.

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“Moral properties are, on this view, higher-order properties—ways of having more basic, natural properties that play certain roles in our practices of evaluation and deliberation.”
— Frank Jackson, From Metaphysics to Ethics (1998)

A given natural property (for example, causing suffering under certain conditions) realizes a moral property (such as wrongness) if it plays the role specified by our concept of that moral property.

7.2 Moral Realism and Objectivity

Jackson defends a form of moral realism and objectivity. In “Objectivity and Truth: You’d Better Believe It” (1992), he argues that talk of objective truth, including in morality, is indispensable. His functionalism aims to show how moral facts can be both objective and naturalistically acceptable: moral properties are realized by natural properties that fill the relevant functional roles.

Supporters see this as reconciling robust moral truth with a scientifically oriented worldview. Critics contend that tying moral properties too closely to our practices risks a form of relativism or constructivism, or that the functional roles cannot capture the full normative force of morality.

7.3 Relationship to Other Metaethical Views

Jackson’s position is often compared with:

Debate continues over whether Jackson’s functionalism adequately accounts for normative authority and motivational internalism, with some arguing that functional roles secure these features, and others maintaining that something more than role-filling natural properties is required.

8. Methodology and Conceptual Analysis

8.1 Defense of Conceptual Analysis

Jackson is a leading contemporary defender of conceptual analysis as a central philosophical method. In From Metaphysics to Ethics, he portrays philosophy as concerned with working out “what we are committed to by our own thought and talk.”

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“Conceptual analysis is a way of working out what we are committed to by our own thought and talk, and that is why it matters to metaphysics and to ethics.”
— Frank Jackson, From Metaphysics to Ethics (1998)

On this view, by systematically reflecting on the conditions under which we apply concepts like “knowledge,” “cause,” “mind,” or “right,” philosophers can uncover the a priori structure of these concepts.

8.2 The A Priori and Its Limits

Jackson treats conceptual analysis as yielding a priori but revisable knowledge. Analyses are constrained and corrected by empirical science: our best theories about the world can lead us to revise our concepts or our understanding of them. The resulting picture is sometimes described as “armchair philosophy with empirical constraint.”

Supporters argue that this approach illuminates how philosophical inquiry can be both conceptually grounded and scientifically informed. Critics, including experimental philosophers and some naturalists, question the reliability of intuitions elicited in thought experiments, or argue that conceptual facts do not straightforwardly yield substantive metaphysical conclusions.

8.3 Intuitions, Thought Experiments, and Revision

Jackson’s own trajectory—particularly his reversal on the knowledge argument—has been cited in discussions about the role of intuitions. He continues to regard intuitions about cases as important data for conceptual analysis but emphasizes their fallibility and the need for integration with broader theoretical virtues and scientific evidence.

Alternative methodologies—such as purely naturalistic philosophy, experimental philosophy, or quietism—challenge Jackson’s approach by downplaying the role of a priori conceptual work or by denying that such work yields substantive metaphysics. His writings remain a central reference point in these debates.

9. Impact on Analytic Philosophy and Debates on Mind

9.1 Influence of the Knowledge Argument

Jackson’s knowledge argument has been one of the most discussed arguments in philosophy of mind since the 1980s. It has shaped debates about:

• Physicalism vs. dualism: Many anti-physicalists (including some property dualists and panpsychists) have used Mary-style arguments as key motivations.
• Types of knowledge: The distinction between propositional, ability, and acquaintance knowledge has been sharpened partly in response to Jackson’s example.
• Qualia and the explanatory gap: The Mary case is a paradigmatic illustration in discussions of whether physical accounts can explain conscious experience.

Even philosophers who reject Jackson’s original anti-physicalist conclusion often frame their views in response to his argument.

9.2 Methodological and Metaphysical Impact

Jackson’s later physicalist reinterpretation of Mary has become a prominent case study in how thought experiments can be re-evaluated. It has influenced discussions on:

• The evidential status of intuitions and the reliability of armchair reasoning.
• How to reconcile the phenomenological pull of anti-physicalist arguments with a commitment to physicalism.
• The role of modes of presentation and phenomenal concepts in explaining apparent gaps between physical and phenomenal descriptions.

In metaphysics and philosophy of language, his work on conditionals, possible worlds, and properties has been integrated into broader frameworks used by many analytic philosophers, even when they diverge from his particular conclusions.

9.3 Impact in Ethics and Metaethics

Jackson’s analytic moral functionalism has contributed to the development of naturalistic approaches to moral realism. It is frequently discussed alongside other functionalist or reductionist views, such as those of Richard Boyd and David Lewis. His defense of objectivity and truth has influenced debates about whether moral discourse is best understood in realist, expressivist, or constructivist terms.

9.4 Institutional and Pedagogical Influence

Through long-standing roles at the Australian National University and collaborations with philosophers at Princeton and elsewhere, Jackson has played a part in shaping the Australasian and global analytic communities. His students and co-authors have gone on to contribute to debates in mind, metaphysics, and metaethics, extending his influence beyond his own publications.

10. Legacy and Historical Significance

10.1 Place within the Analytic Tradition

Jackson is widely regarded as a central figure in late twentieth-century analytic philosophy, particularly within the Australasian tradition. His work exemplifies a style that combines:

• Careful, case-driven argumentation,
• Engagement with formal tools (such as possible worlds semantics), and
• Respect for empirical science.

Within this context, he is often grouped with figures like D. M. Armstrong, J. J. C. Smart, and David Lewis, while occupying a distinctive position due to his sustained focus on conceptual analysis and his dramatic shift regarding physicalism.

10.2 Lasting Contributions

Historically, Jackson’s legacy rests on several enduring contributions:

10.3 Case Study in Philosophical Revision

Jackson’s public retraction of his original anti-physicalist conclusion is frequently cited as an instructive example of philosophical self-correction. Historians and methodologists of philosophy have treated his trajectory as illustrating how:

• Thought experiments can initially seem decisive yet later be reinterpreted.
• Commitments to broad theoretical frameworks (like physicalism) interact with local argumentation.
• A philosopher can maintain methodological continuity (conceptual analysis) while revising substantive metaphysical views.

10.4 Ongoing Assessment

Assessments of Jackson’s significance vary. Some commentators highlight the enduring power of the knowledge argument and question the success of his physicalist response. Others emphasize his contributions to integrating metaphysics, ethics, and methodology into a coherent program. There is also debate over the long-term viability of his robust defense of conceptual analysis in light of experimental philosophy and naturalistic critiques.

Despite divergent evaluations, Jackson’s work remains a touchstone in multiple subfields, ensuring him a continuing place in the history of analytic philosophy and in ongoing debates about mind, reality, and the methods of philosophical inquiry.