Thomas Reid

1. Introduction

Thomas Reid (1710–1796) is widely regarded as the founder of the Scottish School of Common Sense and one of the most systematic critics of early modern skepticism and the ideal theory of ideas. Writing in the context of the Scottish Enlightenment, he defended the reliability of ordinary cognitive practices—perception, memory, testimony, and moral judgment—against the skeptical challenges posed by figures such as David Hume.

Reid’s central claim is that human knowledge ultimately rests on first principles of common sense: basic, non‑inferential convictions that are part of our natural constitution, such as belief in a continuing external world, in other minds, and in the general trustworthiness of our faculties. He argued that these principles are not conclusions of reasoning but conditions of its possibility.

In epistemology and the philosophy of mind, Reid developed a distinctive direct realist account of perception. Against the view that we are immediately aware only of internal ideas or representations, he maintained that in ordinary perception we are directly aware of external objects themselves. He supplemented this with an account of sensation, natural signs, and suggestion to explain how sensory experience gives rise to object-directed thought and belief.

Reid’s work extends beyond perception and epistemology. In his later Essays on the Active Powers of Man he articulated an influential theory of moral agency, active power, and moral liberty, arguing that human beings possess genuine freedom and are therefore appropriate subjects of praise and blame. His writings on language, testimony, and natural theology integrate these themes into a broader theistic and moral framework.

Although his influence waned in the later 19th century, Reid’s ideas shaped Scottish, British, and especially American philosophy, and have experienced a substantial revival in contemporary debates about perception, foundationalism, and free will. The following sections examine his life, works, and doctrines in detail, situating them within both his historical milieu and ongoing philosophical discussion.

2. Life and Historical Context

Reid’s life spanned much of the 18th century, placing him at the heart of the Scottish Enlightenment, a period of intense intellectual, scientific, and institutional development in Scotland. Born in rural Kincardineshire in 1710 into a clerical family, he moved between parish ministry and university life, eventually occupying a central chair in moral philosophy at Glasgow.

Biographical Overview

Scottish Enlightenment Setting

Reid’s career unfolded alongside that of Hume, Smith, Hutcheson, Kames, and others who were rethinking morality, politics, religion, and science. Universities in Aberdeen and Glasgow were sites of curricular reform and debate over Newtonian science, natural religion, and moral philosophy. Reid participated in this culture through:

• The Aberdeen Philosophical Society, an Enlightenment discussion club.
• Engagement with Newtonian physics and the emerging prestige of experimental science.
• Ongoing ecclesiastical debates in the Church of Scotland, including concerns over orthodoxy and the role of reason in religion.

Historians differ on how “radical” the Scottish Enlightenment was. Some portray Reid as a conservative defender of traditional belief against Humean skepticism; others emphasize his alignment with Enlightenment commitments to empirical inquiry, intellectual autonomy, and institutional reform, albeit framed through a theistic and common‑sense lens.

3. Education, Ministry, and Early Influences

Reid’s early formation combined traditional Scottish university training with pastoral experience in a rural parish, shaping both the style and content of his later philosophy.

Marischal College and Intellectual Formation

Reid entered Marischal College, Aberdeen, around age twelve. The curriculum exposed him to:

• Classical languages and rhetoric, providing tools for precise argument and analysis.
• Mathematics and natural philosophy, increasingly taught in a Newtonian framework.
• Moral and natural theology, as integrated parts of the arts curriculum.

Scholars note that this broad training encouraged a suspicion of purely speculative systems detached from observation, a disposition that would later surface in his criticism of the “ideal theory” and his insistence on the evidential role of common experience.

Possible early influences include:

Ministry at New Machar (1737–1752)

Ordained in 1737, Reid served as minister of New Machar. Parish records and later recollections suggest that:

• Pastoral encounters with doubt, sin, and moral conflict fostered his concern with practical reasoning and ordinary belief.
• The need to communicate doctrine to non‑specialists cultivated his preference for clear, accessible language and his respect for “common sense.”
• Conflicts within the parish over his appointment may have sensitized him to issues of testimony, trust, and authority that recur in his later work.

Some interpreters argue that these ministerial years pushed Reid toward a moderate, practical orientation in philosophy, aiming to protect ordinary religious and moral life from what he saw as the destructive implications of skepticism. Others caution against overemphasizing pastoral motives, pointing instead to broader intellectual currents in Aberdeen and beyond as primary drivers of his philosophical development.

4. Aberdeen Philosophical Society and the Scottish Enlightenment

After leaving parish ministry, Reid entered a more explicitly intellectual milieu at King’s College, Aberdeen, where he co‑founded the Aberdeen Philosophical Society (often called the “Wise Club”). This association played a central role in the gestation of his mature views.

The Aberdeen Philosophical Society

Founded in the early 1750s, the Society brought together figures such as George Campbell, James Beattie, and other Aberdeen academics and clergy. Members read and discussed papers on:

• Epistemology and theology, including responses to Hume’s skepticism.
• Rhetoric and the theory of evidence.
• Scientific method and the legitimacy of induction.

Reid’s early drafts of what became the Inquiry were presented here and shaped by feedback from fellow members. The Society’s minutes and surviving papers show a sustained preoccupation with:

Place within the Scottish Enlightenment

The Aberdeen circle is sometimes contrasted with the more commercially and politically oriented Enlightenment in Edinburgh and Glasgow. While sharing Newtonian and empiricist commitments, the Aberdeen philosophers tended to:

• Place greater emphasis on religious orthodoxy.
• Treat common sense as a bulwark against both religious and philosophical skepticism.
• Engage closely with rhetoric and rhetoric‑based epistemology, as in Campbell’s Philosophy of Rhetoric.

Interpretations differ on whether this constitutes a relatively conservative strand of the Scottish Enlightenment or a distinctive attempt to integrate Enlightenment science and rhetoric with Reformed theology. In any case, the Society provided the collaborative environment in which Reid developed his critique of the ideal theory and his first articulation of common‑sense principles.

5. Glasgow Professorship and Academic Career

In 1764 Reid succeeded Adam Smith as Professor of Moral Philosophy at the University of Glasgow, a chair previously held by Francis Hutcheson. This appointment placed him in a prestigious institutional lineage and expanded both his teaching responsibilities and his intellectual audience.

Teaching and Curriculum

As Professor of Moral Philosophy, Reid’s duties extended well beyond narrow ethical theory. His publicly advertised course typically covered:

Students’ lecture notes, later partially published, indicate that Reid integrated his views on perception, evidence, and active powers into these subjects, emphasizing the role of reliable faculties and moral agency in social and legal arrangements.

Academic Networks and Influence

Glasgow’s intellectual environment brought Reid into closer contact with:

• Former colleagues and students of Hutcheson and Smith, situating his work within ongoing debates about moral sense, utility, and virtue.
• A broader British and European readership for his already published Inquiry.
• Students who would later transmit his ideas in Scotland and abroad.

During his Glasgow years, Reid also revised his Inquiry and composed the material that would become his two major essay collections. He retired from active teaching in 1781 but continued to live in Glasgow, working on his manuscripts and corresponding with figures such as Dugald Stewart at Edinburgh, thereby shaping the next generation of Scottish philosophy.

Some historians portray Reid’s Glasgow period as a transition from a primarily polemical critic of the ideal theory to a more systematic philosopher of mind and action. Others argue that the core of his system was already in place in Aberdeen, with the Glasgow years largely devoted to elaboration and pedagogy.

6. Major Works and Their Composition

Reid’s philosophical views are chiefly articulated in three major works, supplemented by lectures and correspondence. Their composition and publication history illuminate the development of his thought.

An Inquiry into the Human Mind on the Principles of Common Sense (1764)

Composed largely during his Aberdeen years and finalized as he moved to Glasgow, the Inquiry focuses on:

• Critiquing the ideal theory of perception.
• Defending direct realism and the trustworthiness of the senses.
• Introducing principles of common sense as philosophical foundations.

Manuscript evidence and Wise Club papers suggest a gradual sharpening of his arguments against Hume and against the representationalist tradition of Descartes, Locke, and Berkeley. Some scholars view the Inquiry as still relatively programmatic, with terminology and distinctions later refined in the Essays.

Essays on the Intellectual Powers of Man (1785)

Written primarily after his move to Glasgow and published post‑retirement, this work systematizes Reid’s theory of the epistemic faculties. It contains essays on:

These essays aim to provide a comprehensive account of how the human mind acquires knowledge and operates in reasoning. Critics debate whether the Intellectual Powers represents a significant shift from the Inquiry or mainly a clarification and expansion.

Essays on the Active Powers of Man (1788)

The companion volume turns to agency, will, and morality. It addresses:

• The distinction between active and passive power.
• The nature of moral liberty and responsibility.
• Principles of moral judgment and virtue.
• The relation between divine providence and human freedom.

Some commentators see these essays as extending his common‑sense foundationalism into ethics and metaphysics of action; others emphasize their relatively independent argumentative structure, especially in discussions of freedom and causation.

Lectures and Correspondence

Additional material comes from:

• Lectures on the fine arts and moral philosophy, preserved in student notes.
• Correspondence with contemporaries like James Gregory and Dugald Stewart.

These sources often clarify points left obscure in the printed works, such as Reid’s precise understanding of signs, language, and the scope of common sense, and inform modern reconstructions of his system.

7. Core Philosophy: Common Sense and First Principles

At the heart of Reid’s system lies his doctrine of common sense and first principles, which he presents as the ultimate foundations of human knowledge and practice.

Common Sense and Natural Belief

Reid uses “common sense” to denote a set of natural, irresistible convictions that arise from the very constitution of human beings. These beliefs:

• Are not derived from argument or inference.
• Are presupposed in all serious reasoning and action.
• Include, for example, belief in a stable external world, in enduring selves, and in other intelligent agents.

He writes of such principles:

"

“If there are certain principles, as I think there are, which the constitution of our nature leads us to believe, and to which we are determined by a kind of natural instinct, these are what we call the principles of common sense.”

— Thomas Reid, Inquiry, II.vi

Reid maintains that to question these principles wholesale is practically impossible and theoretically self‑defeating, since any skeptical argument already relies on them.

First Principles and Their Status

Reid distinguishes several kinds of first principles (e.g., of contingent truths, of necessary truths, of morals, of taste). He characterizes them as:

• Non‑inferentially known: they do not rest on prior proofs.
• Self‑evident to mature, sound understanding.
• Indispensable for reasoning, science, and everyday life.

He proposes criteria for recognizing first principles, such as their universality among properly functioning adults and the absurdity of doubting them in practice. These criteria have been interpreted both as epistemic markers and as descriptive features of human psychology.

Philosophical Role and Critiques

For Reid, first principles function as foundations in a moderate foundationalist epistemology. They:

• Provide initial justification for our faculties (the principle of credulity).
• Underwrite the authority of perception, memory, and testimony.
• Set limits on legitimate philosophical doubt.

Supporters see this as an early articulation of a non‑inferential, externalist justification of basic beliefs. Critics have raised concerns about:

• Circularity: appealing to common opinion to justify what counts as a first principle.
• Relativity: whether “common sense” varies across cultures and eras.
• Conservatism: the risk of immunizing widespread prejudices from critique.

Different interpreters disagree on whether Reid offers primarily a descriptive psychology, a normative epistemology, or a hybrid of both, but there is broad agreement that his appeal to first principles shapes all subsequent aspects of his thought.

8. Epistemology and the Rejection of the Ideal Theory

Reid’s epistemology is largely structured as a response to what he calls the ideal theory or theory of ideas, which he takes to dominate early modern philosophy from Descartes to Hume.

The Ideal Theory as Target

According to Reid’s reconstruction, the ideal theory holds that:

• We are immediately aware only of internal ideas or images.
• Our knowledge of external objects is indirect, inferred from these ideas.
• The mind is therefore confined within a “veil of ideas.”

Reid argues that this framework leads naturally to several forms of skepticism:

Reid’s Positive Epistemology

Against this, Reid advances an epistemology anchored in trustworthy faculties and first principles:

• Perception gives immediate knowledge of external objects.
• Memory reliably informs us about the past.
• Consciousness assures us of our own present thoughts and feelings.
• Testimony is prima facie credible due to the principles of credulity and veracity.

Reid classifies types of evidence (e.g., intuitive, demonstrative, moral) and seeks to show that our practices of belief‑formation are, by and large, rational given our natural constitution. He does not claim infallibility; instead, he emphasizes fallible but properly basic justification.

Critique of Skepticism and Alternative Readings

Reid contends that radical skepticism is “refuted by the constitution of our nature,” since no one can consistently live according to its conclusions. Some commentators see this as a pragmatic or transcendental argument: any attempt to doubt everything presupposes trust in memory, language, and inference. Others interpret Reid more modestly as offering a rebutting defeater: the very success of science and ordinary life provides indirect support for our faculties.

Critics argue that Reid underestimates the possibility of systematic error and cultural bias in common beliefs, and that his appeal to natural instincts may not satisfy contemporary demands for non‑circular justification. Nonetheless, his rejection of the ideal theory and his reorientation toward direct acquaintance with objects significantly influenced later realist and externalist epistemologies.

9. Philosophy of Perception and Direct Realism

Reid’s philosophy of perception is one of his most distinctive contributions. It combines direct realism with a nuanced account of sensation, perception, and natural signs.

Sensation vs. Perception

Reid sharply distinguishes:

• Sensation: a subjective feeling or modification of mind (e.g., a pain, a color sensation), which by itself is neither true nor false.
• Perception: an act in which the mind becomes immediately aware of an external object, accompanied by a belief in its existence and certain of its qualities.

He argues that sensations, by a process of natural suggestion, lead us to perceive external things:

Direct Realism

Reid’s direct realism holds that:

• In normal perception, the immediate object of consciousness is the external thing itself, not an internal idea.
• Perceptual error and illusion do not require intermediaries; they involve misinterpretation of signs or abnormal circumstances.
• The so‑called “visible figure” or “sensible appearance” functions as a sign of the tangible object and its spatial properties.

He insists:

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“In perception, the external object is the immediate and not the mediate object of the mind’s attention.”

— Thomas Reid, Essays on the Intellectual Powers, II.xiv

Natural Signs and Spatial Perception

Reid develops an account of natural signs, especially in vision and touch. For example:

• Certain retinal sensations naturally signify distance, shape, and size.
• Through experience and possibly innate connections, we learn to read these sensations as signs of three‑dimensional objects.

This sign‑relation is not viewed as a conscious inference but as a built‑in or habituated association. Some scholars see this as anticipating later intentionalist or information‑theoretic accounts of perception; others argue that it remains closer to a faculty psychology with sui generis perceptual powers.

Critical Assessments

Supporters praise Reid for:

• Exposing difficulties in the “veil of ideas” model.
• Highlighting the world‑directed character of perceptual experience.
• Clarifying the role of non‑doxastic elements (sensations) in perception.

Critics raise questions about:

• How to understand “immediate” perception given the complexity of sensory processing.
• Whether his appeal to natural signs covertly reintroduces a representational element.
• The status of secondary qualities (color, sound) within his realism.

These debates have made Reid a central reference point in contemporary discussions of naïve realism, disjunctivism, and the phenomenology of perception.

10. Metaphysics of Mind, Self, and Causation

Reid’s metaphysics undergirds his epistemology and ethics, especially in his accounts of mind, personal identity, and causal power.

The Nature of Mind and Personal Identity

Reid portrays the mind as a simple, indivisible, active substance distinct from matter. He rejects both materialist and purely bundle‑theoretic conceptions of the self, arguing that:

• Consciousness reveals acts of thought, not the underlying substance itself.
• Nevertheless, we have an immediate conviction of our continued existence as the same being over time.
• Memory contributes to our knowledge of past states but does not constitute identity.

In opposition to Hume’s bundle theory, Reid insists that personal identity is a first principle, known non‑inferentially and presupposed in all moral and practical deliberation. Some commentators view this as a defense of substance dualism; others argue that he is committed only to a minimal, active subject of mental attributes, leaving many metaphysical questions open.

Causation and Active Power

Reid draws a sharp distinction between:

• Efficient causes, which are agents with active power.
• Mere occasions or antecedents, which may be regularly conjoined with effects but lack genuine efficacy.

He argues that:

• The only causes we directly understand are ourselves as agents, when we intentionally bring about actions.
• Our notion of causation is thus rooted in experience of exerting power, not in the passive observation of regularities.
• Material objects, as such, possess only passive power; true efficiency belongs to minds (finite and divine).

This leads to a form of agent‑causal realism. Reid opposes both Humean regularity theories and certain forms of occasionalism, although his precise stance on how divine and human causation interact is interpreted in different ways.

Philosophical Implications and Debates

Reid’s metaphysics supports:

• The unity and responsibility of the self.
• The reality of freedom as an exercise of active power (developed more fully in his ethics).
• A world structured by mind‑based causation within a divinely governed order.

Critics question whether his thin account of mental substance goes beyond a bare logical subject, and whether his appeal to agent causation can avoid explanatory regress. Nonetheless, his insistence on mental activity and causal power has influenced later debates on free will, mental causation, and the ontology of persons.

11. Ethics, Active Powers, and Moral Liberty

Reid’s ethical theory centers on his conception of active powers and moral liberty, presented chiefly in the Essays on the Active Powers of Man.

Active Powers and Moral Agency

Reid distinguishes between:

• Active power: the capacity to bring about effects in accordance with the determination of one’s will.
• Passive power: the capacity merely to be affected by other causes.

He defines:

"

“Power to act according to the determination of our will, is what we call active power.”

— Thomas Reid, Essays on the Active Powers, I.i

Human beings, as rational agents, possess active powers that make them proper subjects of moral evaluation. He regards:

• Understanding (intellectual powers) as informing us about facts and relations.
• Will and affections as directing action.
• Conscience or the moral faculty as judging right and wrong.

Moral Liberty and Responsibility

Reid defends moral liberty—the power to do or forbear, and to act otherwise under the same circumstances—against both:

• Necessitarianism, which holds that every action is determined by prior causes.
• Purely indeterministic views that deny any rational control.

His view is often classified as libertarian in the sense that genuine alternatives are open to the agent and that free actions are not strictly determined by antecedent states. He contends that moral responsibility presupposes such liberty; without it, praise and blame would be inappropriate.

Moral Principles and Virtue

Reid also articulates:

• First principles of morals, such as the obligation to keep promises, to seek the good of others, and to respect justice.
• A conception of virtue as conformity of character and conduct to these moral truths, known through a combination of reason and moral sensibility.

He differs from Hutcheson’s moral sense theory by giving a larger role to rational discernment of self‑evident moral truths, while still acknowledging affective elements in moral judgment.

Interpretive and Critical Questions

Commentators debate:

• Whether Reid’s libertarianism can be reconciled with his strong commitment to divine foreknowledge and providence.
• How his moral first principles relate to cultural variation and historical change.
• The extent to which his ethics is intuitionist versus rationalist.

Despite these issues, his integration of free agency, moral law, and common‑sense convictions remains influential in discussions of responsibility and ethical realism.

12. Language, Natural Signs, and Testimony

Reid’s reflections on language and signs connect his philosophy of perception with his account of communication and testimony as a source of knowledge.

Natural and Artificial Signs

Reid distinguishes between:

• Natural signs: features of experience that, by our constitution, immediately suggest something else (e.g., facial expressions suggesting emotions, visual sensations suggesting spatial properties).
• Artificial signs: conventional symbols, especially words in a language, whose meaning depends on human institution.

He suggests that natural signs form the original language of nature, on which artificial languages are built. For example:

This framework underlies his accounts of both perception (where sensations are natural signs of external objects) and interpersonal understanding.

Testimony, Credulity, and Veracity

Reid argues that human beings are endowed with:

• A principle of credulity: a natural inclination to believe what others tell us.
• A principle of veracity: a natural inclination to speak the truth.

These principles make testimony a basic and legitimate source of knowledge, on a par with perception and memory in its fundamental status. He contends that our extensive reliance on others in acquiring information would be irrational unless these principles were generally trustworthy.

Reid’s view contrasts with attempts to reduce testimonial knowledge to personal observation or inductive evidence about a speaker’s reliability. He instead treats acceptance of testimony as prima facie justified by our constitution, defeasible in the presence of specific counter‑evidence.

Contemporary Interpretations and Critique

Modern epistemologists have drawn on Reid to support anti‑reductionist theories of testimony, which hold that testimonial justification is not always inferential from other kinds of evidence. Supporters see him as anticipating externalist accounts of justification based on reliable social practices.

Critics raise concerns about:

• The extent of cultural and historical variation in norms of truth‑telling.
• Whether an appeal to natural propensities suffices for epistemic justification.
• How to handle systematic deception or propaganda within his framework.

Nonetheless, Reid’s linkage of natural signs, language, and testimony has been influential in both the philosophy of language and social epistemology.

13. Religion, Natural Theology, and Theism

Reid’s philosophical work is embedded within a broadly theistic framework, reflecting his lifelong commitment as a minister and theologian, yet he also engages with questions of natural theology in a characteristically Enlightenment manner.

Theistic Background

Reid operated within the Reformed (Presbyterian) tradition of the Church of Scotland. His writings assume:

• The existence of a personal, wise, and benevolent God.
• A world ordered by divine providence.
• Human beings as created with faculties designed for truth and moral goodness.

He saw his defense of common sense as compatible with, and in some respects supportive of, traditional Christian doctrines, though he rarely engages in detailed dogmatic theology in his philosophical works.

Natural Theology and Arguments for God

In his lectures and essays, Reid offers and endorses several lines of reasoning for God’s existence, including:

• Cosmological‑style considerations: the dependence of contingent beings and events on a first cause.
• Design arguments: the complexity and order of nature, especially the human mind and moral faculties, as indicative of intelligent design.
• Moral arguments: the objectivity of moral obligations suggesting a moral lawgiver.

These arguments, he maintains, are accessible to natural reason and do not depend solely on revelation. He treats them as forms of probable or moral evidence sufficient for rational belief.

Providence, Freedom, and Evil

Reid holds that divine providence is compatible with human moral liberty. Interpretations of this relationship vary:

• Some read him as endorsing a form of concurrentism, where God sustains and cooperates with human actions without determining them.
• Others emphasize unresolved tensions between his agent‑causal libertarianism and strong claims about divine foreknowledge.

On the problem of evil, Reid tends to emphasize:

• Human misuse of freedom as a primary source of moral evil.
• The limitations of human understanding in comprehending divine purposes.

He does not develop a systematic theodicy, but his defense of the trustworthiness of our faculties is sometimes seen as part of a broader argument for a benevolent creator.

Religion and Enlightenment Thought

Reid shares with many Scottish Enlightenment figures a commitment to:

• Natural religion as a rational enterprise.
• The integration of religious belief with science and common life.

Scholarly debate continues over how far his theism shapes his epistemology. Some view his appeal to common sense as largely independent of specifically Christian commitments; others interpret it as deeply informed by a theistic conception of human nature and cognitive design.

14. Critique of Hume and Engagement with Early Modern Philosophy

Reid’s work is deeply engaged with the early modern tradition, especially with David Hume, John Locke, and George Berkeley. His critique is both historical and systematic.

Engagement with Hume

Reid read Hume’s Treatise and Enquiry carefully and took them as serious challenges. He credits Hume with exposing the implications of the ideal theory, while rejecting those implications as unacceptable. Key points of engagement include:

Reid sees Hume as having “reasoned justly from principles which he learned from Locke and Berkeley,” but contends that those principles must be rejected rather than accepted with skeptical consequences.

Relation to Locke and Berkeley

Reid groups Descartes, Locke, Berkeley, and Hume under the heading of the ideal theory, though he recognizes significant differences among them. He criticizes:

• Locke’s account of ideas as leading to representationalism and skepticism.
• Berkeley’s rejection of matter as an overreaction to problems created by the ideal theory itself.

At the same time, he acknowledges the empiricist emphasis on experience and often appeals to common experience in a way partially continuous with them. Some scholars argue that Reid’s reading of Locke and Berkeley oversimplifies their positions; others see his polemical reconstruction as historically motivated but philosophically productive.

Position within Early Modern Debates

Reid can be situated within several ongoing controversies:

• Rationalism vs. empiricism: He rejects both rationalist deduction from innate ideas and a narrow empiricism limited to sensations, proposing instead a common‑sense empiricism grounded in everyday experience and first principles.
• Skepticism vs. dogmatism: He opposes radical skepticism while allowing for fallible, corrigible knowledge.
• Realism vs. idealism: He defends a robust realism about the external world, the self, and causal powers.

Interpreters dispute whether Reid offers a fundamentally new paradigm or a conservative corrective to the tradition. What is generally agreed is that his engagement with early modern philosophy is not merely negative; it reshapes inherited problems around a different set of assumptions about perception, belief, and the mind.

15. Reception in Scotland, Britain, and North America

Reid’s ideas were taken up, modified, and sometimes contested across Scotland, the wider British Isles, and North America in the decades after his death.

Scottish and British Reception

In Scotland, Dugald Stewart at Edinburgh became the principal expositor of Reid’s philosophy. Stewart’s lectures and writings:

• Popularized common‑sense principles and Reid’s critiques of skepticism.
• Sometimes softened Reid’s metaphysical commitments, emphasizing methodological and pedagogical aspects.
• Helped establish the Scottish Common Sense School as a recognized movement.

Other figures, such as James Beattie and George Campbell, had already shared many of Reid’s concerns. Over time, elements of common‑sense philosophy were incorporated into broader educational curricula in Scottish universities.

In England and Ireland, Reid’s influence was more mixed:

• Some Anglican and dissenting theologians adopted his arguments against skepticism and in favor of theism.
• Critics associated with emerging idealism and later empiricism were less sympathetic, regarding common sense as philosophically insufficient.

North American Reception

Reid’s work had notable impact in North American colleges and seminaries, particularly in the late 18th and 19th centuries. His writings, often mediated through Stewart, became standard texts in:

• Moral philosophy courses.
• Rhetoric and logic instruction.
• Theology and apologetics.

At institutions like Princeton, Yale, and various Presbyterian seminaries, common‑sense principles were used to defend:

• The reality of moral and religious knowledge.
• The reliability of human faculties against both deism and skepticism.

Shifts in Reputation

Over the 19th century, Reid’s prominence declined in Britain as:

• German idealism and then British idealism gained influence.
• New forms of empiricism and scientific naturalism questioned faculty psychology and first principles.

In contrast, aspects of his thought persisted longer in North American contexts, especially among theologians and philosophers sympathetic to realist and theistic frameworks. By the early 20th century, however, even there his name was less frequently invoked explicitly, though some of his themes continued indirectly.

16. Influence on American Philosophy and Realism

Reid’s impact on American philosophy was particularly pronounced in the 19th century, helping to shape various forms of realism and theological thought.

Scottish Common Sense in American Colleges

Through the importation of Scottish textbooks and the recruitment of Scottish‑trained faculty, Reid’s ideas—often via Dugald Stewart—dominated moral and mental philosophy curricula at institutions such as:

Common‑sense philosophy was seen as providing a philosophical underpinning for:

• Belief in an external world and moral truths.
• Confidence in the general reliability of human cognition.
• Opposition to both radical skepticism and materialism.

American Realism and Anti‑Idealism

In the late 19th and early 20th centuries, American philosophers associated with realist movements sometimes appealed, explicitly or implicitly, to Reidian themes:

• New Realists and Critical Realists favored direct or critical realism about perception and external objects.
• The emphasis on mind‑independent reality and the rejection of “ideas as intermediaries” resonate with Reid’s critique of the ideal theory.

While these thinkers often did not adopt Reid’s full framework (especially his theology and faculty psychology), historians have noted family resemblances between his direct realism and later American realist doctrines.

Theological and Apologetic Uses

American theologians used Reidian common sense to argue that:

• Basic religious and moral beliefs enjoy prima facie justification.
• Skeptical challenges can be met by appealing to the natural constitution of human beings.

Some interpret this as a fruitful contextualization of Reid’s ideas in a new environment; others see it as a selective appropriation that downplays his more nuanced philosophical distinctions.

Overall, Reid’s influence in America contributed to a lasting realist and theistic strand within the philosophical landscape, even as pragmatism and other currents later came to prominence.

17. Reid in Contemporary Epistemology and Philosophy of Mind

From the late 20th century onward, Reid has experienced a significant revival, particularly in Anglophone analytic philosophy.

Contemporary Epistemology

Reid’s views have been revisited in discussions of:

• Foundationalism: His appeal to first principles is seen as a model of moderate foundationalism, where basic beliefs are fallible but not inferred from others.
• Externalism: The idea that the reliability of faculties can confer justification without the subject’s reflective access parallels externalist accounts of warrant.
• Testimony: Reid is frequently cited as an early proponent of anti‑reductionism about testimonial knowledge.

Philosophers such as Nicholas Wolterstorff, Alvin Plantinga, and others have drawn on Reidian themes to develop reformed epistemology, though interpretations vary on how closely they track Reid’s own positions. Some adopt his trust in properly functioning faculties while revising his specific list of first principles or his faculty psychology.

Critics in contemporary epistemology question whether Reid’s criteria for first principles are sufficiently rigorous and whether his reliance on “common sense” can address disagreement and cognitive bias.

Philosophy of Mind and Perception

Interest in Reid has also grown in the philosophy of mind, especially concerning:

• Naïve realism and disjunctivism: Reid’s insistence that we are directly aware of external objects, and that illusions are exceptional, has been compared to contemporary naïve realist views.
• Intentionality and representation: His notion of natural signs and the distinction between sensation and perception are seen as anticipating certain intentionalist or information‑based theories, though he does not formulate them in representationalist terms.
• Self and agency: Debates about the unity of consciousness, personal identity, and agent‑causal theories of free will often reference his positions as historically significant precursors.

Some contemporary philosophers find in Reid a useful alternative to both phenomenalism and strict reductive physicalism, while others argue that his dualistic tendencies and faculty psychology sit uneasily with current scientific understandings of the mind.

Assessment

Scholars differ on how “contemporary” Reid can be made without distortion. One approach treats him as a resource for generating ideas and arguments compatible with present frameworks; another emphasizes the historical integrity of his theistic and faculty‑based system. Despite these disagreements, there is broad consensus that Reid offers a rich set of positions and arguments that engage directly with central questions in current epistemology and philosophy of mind.

18. Legacy and Historical Significance

Reid’s legacy spans multiple domains: early modern philosophy, Scottish Enlightenment thought, American intellectual history, and contemporary analytic debates.

Position in the History of Philosophy

Historically, Reid is often seen as:

• A major alternative to both rationalism and empiricism, emphasizing common‑sense foundations.
• A central figure in the Scottish Common Sense School, influencing education and public discourse in Britain and America.
• An interlocutor who forced later thinkers to confront the implications of skepticism and representationalism.

His work provides a bridge between early modern debates and 19th‑century movements such as British idealism and American realism, even where later thinkers rejected his conclusions.

Influence on Later Traditions

Reid’s ideas contributed to:

• The development of intuitionist ethics and realist moral theories.
• Discussions of free will and agent causation in both theology and philosophy.
• The emergence of analytic philosophy’s concern with clarity, directness, and attention to ordinary language and practice, though this influence is more indirect and contested.

Contemporary Reassessment

Modern scholarship has reassessed Reid in several ways:

• As a sophisticated system‑builder, not merely a popularizer of common sense.
• As a philosopher whose anti‑skeptical strategies and accounts of perception, testimony, and agency anticipate key themes in current analytic philosophy.
• As an important voice for understanding the religious and institutional context of the Scottish Enlightenment.

There is ongoing debate over how to balance historical and systematic readings of Reid, and over how central his theistic assumptions are to his philosophy’s viability. Yet his continued presence in scholarly literature and teaching indicates a durable significance. Reid is now widely regarded not only as a historically important critic of Hume but also as a source of live options in epistemology, philosophy of mind, and moral philosophy.