THOMAS REID

Scottish Common Sense philosopher, Presbyterian minister, professor. Born into educated Presbyterian family (father was minister, mother from scholarly lineage), received excellent education in philosophy and mathematics. Studied at Marischal College, Aberdeen, mastering Newton's physics and Locke's philosophy. Became librarian at Marischal (1733), then Presbyterian minister at New Machar (1737-1751), combining pastoral duties with intellectual work. Appointed professor of philosophy at King's College, Aberdeen (1751), founding Aberdeen Philosophical Society ("Wise Club") with fellow intellectuals discussing Hume's philosophy critically. His Inquiry into the Human Mind (1764) challenged Humean skepticism, establishing Common Sense philosophy. Appointed to succeed Adam Smith as professor of moral philosophy at Glasgow (1764-1780), teaching logic, ethics, politics, natural theology. Gentle, modest personality contrasting with argumentative style — respectful critic of Hume (they were friends despite philosophical disagreement). Married cousin Elizabeth Reid (1740), had nine children. Deeply religious, integrated philosophy with Presbyterian theology. Retired 1780, continuing to write until stroke (1790s) impaired abilities. Died peacefully 1796, age 85. Founded Scottish Common Sense Realism, defending ordinary beliefs against philosophical skepticism through appeal to self-evident first principles. The moderate Presbyterian who made common sense philosophical.

Died October 7, 1796, in Glasgow, age 86; natural death from old age after suffering strokes in final years; died peacefully; buried at Blackfriars churchyard, Glasgow

Not recorded — final years marked by declining health and reduced communication after strokes

Thomas Reid was born April 26, 1710, in Strachan, small village in Kincardineshire (Aberdeenshire), northeast Scotland. His father Lewis Reid was Presbyterian minister. His mother Margaret Gregory came from distinguished scholarly family — her brother David Gregory was professor of mathematics at Oxford, and Aberdeen professors of mathematics for several generations came from Gregory family.

He received excellent early education, entering Marischal College, Aberdeen (1722), age twelve (typical for era). He studied classics, mathematics, natural philosophy (physics), and philosophy. He graduated MA (1726), mastering Newton’s physics and Locke’s philosophy, which dominated curriculum.

After graduation, he remained at Marischal as librarian (1733-1736), continuing studies. In 1737, age 27, he was ordained Presbyterian minister and appointed to parish of New Machar near Aberdeen. For fourteen years (1737-1751), he served as country minister — preaching, conducting services, visiting parishioners, performing baptisms and marriages. But he continued intellectual work, studying mathematics, optics, philosophy.

During this period, he married his cousin Elizabeth Reid (1740). They had nine children, though several died young. His domestic life was stable and happy, providing foundation for intellectual work.

In 1751, he was appointed professor of philosophy at King’s College, Aberdeen, teaching logic, ethics, and metaphysics. His move from ministry to academia was natural — Scottish Presbyterian ministers were often scholars, and Aberdeen’s colleges valued learned clergy.

At Aberdeen, he founded the Aberdeen Philosophical Society (1758), nicknamed “Wise Club,” with fellow intellectuals including George Campbell, James Beattie, and Alexander Gerard. They met fortnightly, presenting papers and debating philosophical questions. Major focus was Hume’s philosophy — Hume’s Treatise of Human Nature (1739-1740) and Enquiries had presented skeptical conclusions following from empiricist premises. Reid and colleagues found Hume’s skepticism about external world, causation, self, and induction philosophically brilliant but ultimately absurd.

Reid developed response: Hume’s skepticism results from false premise — the “way of ideas” inherited from Locke. If we only perceive ideas (mental representations), not external objects directly, then skepticism follows inevitably. We can’t prove external world exists because we’re locked inside our minds perceiving only ideas. Berkeley concluded physical objects are collections of ideas. Hume concluded we can’t know whether external world exists.

Reid’s breakthrough: Reject the “way of ideas” entirely. We perceive external objects directly, not through mental intermediaries. Sensation occasions perception but isn’t object perceived. When I see red ball, I don’t perceive idea of red ball; I perceive red ball itself. This direct realism eliminates skeptical problem.

But how justify direct realism? Reid’s answer: Common sense principles — self-evident truths rational persons accept as foundations of thought. These include: External world exists. Other minds exist. Past events really happened. Memory is generally reliable. Testimony is generally trustworthy. Objects have causal powers. These aren’t proved by argument (that would be circular — proofs presuppose common sense principles like reasoning’s reliability). They’re first principles recognized immediately by rational persons.

He published An Inquiry into the Human Mind on the Principles of Common Sense (1764), presenting these ideas systematically. The book attacked “way of ideas,” defended direct realism, and established common sense philosophy.

The work’s success led to invitation to succeed Adam Smith as professor of moral philosophy at University of Glasgow (1764), Scotland’s premier university. He held position until retirement (1780), teaching logic, moral philosophy, politics, and natural theology to large classes. His Glasgow lectures developed ideas further, though published posthumously.

At Glasgow, he wrote two more major works: Essays on the Intellectual Powers of Man (1785) — systematic treatise on epistemology, perception, memory, judgment, reasoning. Essays on the Active Powers of Man (1788) — treatise on moral philosophy, free will, and ethics. Together these presented comprehensive philosophical system rivaling Hume’s.

Throughout career, he maintained cordial relations with Hume despite philosophical disagreement. They corresponded respectfully, and Reid praised Hume’s intellectual brilliance while rejecting his conclusions. When Hume died (1776), Reid was among philosophers mourning loss while continuing to critique his philosophy.

He retired from teaching (1780), age 70, continuing to write and revise works. His later years were productive until suffering strokes in 1790s reduced his abilities. He died peacefully October 7, 1796, in Glasgow, age 86.

His philosophical legacy was substantial: He founded Scottish Common Sense Realism, dominating Scottish philosophy through 19th century. His student Dugald Stewart spread his ideas, influencing Scottish Enlightenment’s practical emphasis. His philosophy was exported to America, dominating American university philosophy through 19th century (Princeton especially). His direct realism influenced later philosophy — G.E. Moore’s common sense defense, American pragmatists, ordinary language philosophy. His critique of “way of ideas” anticipated phenomenology’s rejection of representationalism.

Negatively, “common sense” became associated with conservatism and anti-intellectualism. Critics mocked appeal to “what everyone knows” as evasion of philosophical responsibility. But Reid’s actual position was more sophisticated — common sense principles are rational foundations, not mere prejudice.

His religious integration of philosophy was both strength and limitation. He used philosophy to defend Christian theism, making philosophical inquiry serve theology. This satisfied Presbyterian culture but limited critical scope.

Overall, he provided powerful alternative to skepticism without dogmatism. Against Hume’s radical doubt, he offered moderate realism. Against rationalist metaphysics, he offered empiricism grounded in common sense. Against idealism, he offered direct realism preserving ordinary beliefs. Whether successful is debated, but he raised enduring questions about foundations of knowledge, self-evidence, and philosophy’s relationship to common sense.

When Inquiry into the Human Mind was published (1764), Reid sent copy to David Hume, whose philosophy he'd critiqued extensively. Hume response was gracious: He thanked Reid, praised his "depth of thought and elegance of expression," but defended his own position politely. Their correspondence continued respectfully. Once, Hume wrote to Reid: "I wish it were still in my power to be a convert to your doctrines. I assure you, I should be much more proud of them than of my own." But he remained unconvinced, finding Reid's common sense principles question-begging — assuming what needed proving. Reid responded equally politely, arguing Hume skepticism was self-refuting — skeptic relies on reasoning and memory while denying their reliability. Their exchange exemplified philosophical disagreement at its best — mutual respect, intellectual honesty, no personal attacks. When Hume died (1776), Reid mourned publicly: "I thought him a very good-natured man, and have always regretted that he should have employed so much good sense and ingenuity in support of principles so pernicious." This captured their relationship — profound philosophical disagreement combined with personal friendship and respect. Critics might see this as avoiding hard confrontation, but it demonstrated that philosophical combat needn't be personal combat. Reid and Hume showed philosophy can be simultaneously adversarial and civil.

Reid wasn't appealing to popular opinion — "common sense" means rational first principles, not majority beliefs or folk wisdom. He wasn't anti-philosophical — he engaged sophisticated epistemology while defending ordinary beliefs. His direct realism wasn't naive — he distinguished sensation (subjective experience) from perception (awareness of object). His common sense principles weren't arbitrary — they're rationally self-evident, necessary for thought and action. He wasn't conservative obscurantist — he challenged dominant philosophy (Hume, Locke) radically. His philosophy wasn't merely defensive — he developed positive theory of perception, knowledge, and agency. He wasn't dismissing arguments — he provided detailed critiques of representationalism. His appeal to self-evidence wasn't dogmatic — he argued first principles require no proof because they're foundational. And his influence wasn't limited to Scotland — he shaped American philosophy profoundly and influenced later movements (ordinary language philosophy, direct realism revival).

Reid broke the "way of ideas" (indirect realism through mental representations) by establishing direct realism and common sense first principles against skepticism. Against Locke, Berkeley, and Hume representationalism (we perceive ideas/impressions mediating between mind and world, leading to skepticism about external reality), he argued: We perceive objects directly, not through mental intermediaries. Sensation provides occasion for perception but isn't object perceived. When I see tree, I perceive tree itself, not idea of tree. The "way of ideas" inevitably produces skepticism — if we only know ideas, how know external world exists? (Berkeley idealism, Hume skepticism followed logically). Reid's solution: Reject representational theory; embrace direct realism. Perception gives immediate awareness of external objects. This rests on common sense principles — self-evident truths all rational persons accept: External world exists. Other minds exist. Memory is generally reliable. Testimony is generally trustworthy. Objects have real causal powers. These aren't proved by argument but accepted as first principles of common sense. Attempting to prove them presupposes them (circular). Denying them is self-refuting (skeptic relies on memory, senses, reasoning while denying their reliability). Against skeptics demanding proof of common sense, Reid argued: First principles are starting points, not conclusions. Demanding proof of everything produces infinite regress. Rational inquiry requires accepting self-evident principles. Critics objected: What makes principles "self-evident"? Doesn't "common sense" vary across cultures? How distinguish genuine common sense from prejudice? Reid responded: Self-evidence means rational persons recognize truth immediately, with adequate understanding. Cultural variation affects applications, not fundamental principles. Genuine common sense is universal, necessary for rational thought and practical life.

Start with Inquiry into the Human Mind Chapters 1-2 and 6 (introduction and conclusion) — most accessible, foundational arguments. Then read Essays on the Intellectual Powers Essay VI (on judgment and common sense) — central epistemology. For secondary literature, read Nicholas Wolterstorff's Thomas Reid and the Story of Epistemology (excellent philosophical analysis). Keith Lehrer and James Van Cleve's introductions to Reid are helpful. Roger Gallie's Thomas Reid: Ethics, Aesthetics and the Anatomy of the Self covers full range. Terence Cuneo and René van Woudenberg's Cambridge Companion to Thomas Reid provides scholarly essays. Understanding requires Hume background — read Hume Enquiry Concerning Human Understanding first. Reid's writing is clearer than Hume, more accessible than Kant, but assumes familiarity with modern epistemology debates.

Reid's influence on American philosophy: Through 19th century, Scottish Common Sense Realism dominated American university philosophy, especially Princeton. John Witherspoon (Reid's student) became Princeton president (1768), bringing Common Sense philosophy. It influenced: American Founding Fathers — Jefferson, Madison, Hamilton read Reid, influencing political philosophy. James McCosh (Princeton president) spread Reid's ideas through American academia. Charles Sanders Peirce engaged Reid seriously, developing pragmatism partly in dialogue with Common Sense philosophy. American realism (New Realists, Critical Realists) echoed Reid's direct realism. Why so influential? Reid's common sense approach suited American pragmatism, democratic values, and Protestant culture. His defense of ordinary beliefs against skepticism resonated with practical-minded Americans suspicious of European philosophical abstraction. His integration of philosophy with religion satisfied Protestant colleges dominating American higher education. His epistemological modesty (acknowledging reasoning's limits, accepting first principles) fit American anti-speculative temperament. This made Reid more influential in America than Britain through 19th century. Only with rise of German idealism, then British analytic philosophy (Russell, Moore), did Reid's influence wane. But his direct realism revival (Moore, American realists) showed enduring appeal. The Scottish minister's philosophy shaped American intellectual culture profoundly.

Imagine wearing glasses. Representationalism (way of ideas) says: You see lenses (ideas), not world directly. Lenses mediate vision. Problem: How know world matches what lenses show? Maybe lenses distort. Can't compare world with lenses (only see through lenses). Berkeley says: World is just lenses — nothing exists except lenses and see-er. Hume says: Can't know whether world exists beyond lenses — maybe it does, maybe it doesn't. Reid says: Analogy is wrong. You don't see lenses; you see through them to world. Remove metaphorical lenses entirely — vision gives direct awareness of world, not awareness of mental intermediaries. When you see tree, you perceive tree itself, not representation of tree. Critics respond: But vision involves retinal images, neural processing — these are intermediaries. Reid: Physiological processes cause perception but aren't objects perceived. Causal mechanism differs from perceptual content. You perceive tree directly despite complex causal chain enabling perception. That's direct realism versus representationalism debate.

Reid developed Common Sense Realism by rejecting representationalism, establishing direct perception, and grounding knowledge in self-evident first principles.

The Way of Ideas: Locke, Berkeley, and Hume shared representationalism: We perceive ideas (mental representations, impressions, sense-data), not external objects directly. Ideas mediate between mind and world. External objects cause ideas, but we know only ideas immediately. This “veil of perception” creates skeptical problem: If we only perceive ideas, how know external world exists matching ideas? Can’t compare ideas with objects (only know ideas). Can’t prove objects cause ideas (causation itself is idea).

Berkeley’s response: Physical objects are collections of ideas. “To be is to be perceived” (esse est percipi). Material substance is incoherent fiction. Only minds and ideas exist. This idealism avoids skepticism (no gap between ideas and reality — ideas are reality) but denies common sense (material objects exist).

Hume’s response: Can’t prove external world, self, causation, or future resembles past. All beliefs rest on custom, not reason. Skepticism is theoretically irrefutable but practically impossible — nature forces us to believe despite lacking rational justification.

Reid’s Diagnosis: “Way of ideas” causes these absurdities. It’s false premise leading to skeptical conclusions. Solution: Reject representationalism entirely. No mental intermediaries exist between mind and world. Perception is direct awareness of external objects.

Direct Realism: When I see tree, I perceive tree itself, not idea of tree. Sensation (subjective experience — feeling, impression) provides occasion for perception but isn’t object perceived. Visual sensation (phenomenal quality) accompanies perceiving tree but differs from tree perceived. This distinguishes: Act of perception (mind’s awareness), Object perceived (external thing), Sensation (accompanying experience).

We’re immediately aware of objects, not through inference from sensations. Perception gives direct acquaintance with external reality. This dissolves skeptical problem — no veil of perception to pierce.

Common Sense Principles: But how justify direct realism against representationalism? Reid’s answer: Common sense principles — self-evident first principles rational persons accept. Examples: External world exists. Other minds exist. Past really happened. Memory is generally reliable. Testimony is generally trustworthy. Objects have causal powers. These can’t be proved without circularity (proofs presuppose reliability of reasoning, memory, perception — the very principles questioned). They’re foundational — starting points for rational inquiry, not conclusions.

Self-Evidence: What makes them self-evident? Not that everyone agrees (many deny them philosophically). Rather: (1) Rational persons with adequate understanding recognize their truth immediately. (2) They’re necessary for thought and action — can’t coherently deny them. (3) Attempting to prove them presupposes them. (4) Denying them is self-refuting — skeptic relies on principles while doubting.

Example: Skeptic questions memory’s reliability. But argument uses memory (remembering past reasoning). If memory is unreliable, argument is worthless. If memory is reliable, skepticism about memory is refuted. Either way, skeptical argument fails.

Against Demanding Proof: Hume and skeptics demand proof of common sense principles. Reid responds: This demand is illegitimate. Rational inquiry requires starting points. If everything requires proof, infinite regress follows — nothing is known. First principles are recognized, not proved. They’re foundations enabling proof of other claims.

Constitution of Nature: Why do we accept first principles? Reid’s answer: Constitution of human nature. We’re created (Reid was theist) with cognitive faculties delivering reliable beliefs. Perception delivers beliefs about external world. Memory delivers beliefs about past. Reason delivers beliefs about logical truths. These faculties are generally reliable by design, though fallible in particular cases.

This anticipates reformed epistemology (Alvin Plantinga) — properly functioning cognitive faculties produce warranted beliefs without needing proof.

Moral Philosophy: Reid applied common sense to ethics. Moral principles are self-evident first principles like intellectual principles. Examples: Benevolence is virtuous. Cruelty is wrong. Justice is obligatory. These are recognized immediately by moral faculty (conscience). They don’t require proof or derivation from non-moral facts (against Hume’s fact-value distinction).

Moral sense theory (Hutcheson) influenced Reid, but he grounded morality in reason, not sentiment alone. Conscience perceives moral truths rationally, like intellect perceives logical truths.

Free Will: Reid defended libertarian free will against Hume’s compatibilism. Determinism: All events, including human actions, are caused by prior events necessitating them. Compatibilism (Hume): Freedom is doing what you want (no external constraint), compatible with determinism.

Reid rejected this: Genuine freedom requires power to cause actions not determined by prior causes. Agents have irreducible active power — ability to initiate causal chains. Moral responsibility requires this libertarian freedom. If actions are determined, praise/blame make no sense.

This raised problems: How can indeterministic actions be rational? If not determined by reasons, are they arbitrary? Reid struggled answering but insisted genuine agency requires libertarian freedom.

Faculty Psychology: Reid employed faculty psychology — mind has distinct faculties (perception, memory, reason, will, conscience) each with characteristic operations. This was common framework (medieval scholasticism, early modern philosophy used it). Critics later questioned whether faculties explain or merely label phenomena.

Reid influenced philosophy significantly: (1) Founded Scottish Common Sense Realism, dominating Scottish philosophy through 19th century. (2) Shaped American philosophy profoundly through 19th century (Princeton especially). (3) Influenced G.E. Moore's common sense defense of ordinary beliefs against idealism. (4) Contributed to ordinary language philosophy (Austin, later Wittgenstein) — defending ordinary usage against philosophical revision. (5) Influenced American New Realism (early 20th century) challenging idealism. (6) Contributed to contemporary direct realism revival in philosophy of perception. (7) Influenced reformed epistemology (Plantinga's proper basicality parallels Reid's first principles). (8) Provided alternative to skepticism without dogmatism — moderate realism. (9) Raised enduring questions about foundationalism, self-evidence, and burden of proof. (10) Defended libertarian free will, influencing action theory. Though criticized for conservatism and question-begging, his insights about perception's directness, foundational principles, and skepticism's practical impossibility remain philosophically vital.

Reid speaks to contemporary philosophy: His direct realism relates to debates in philosophy of perception (sense-data theory versus direct realism). His common sense principles parallel foundationalism in epistemology. His critique of representationalism anticipates phenomenology (Husserl bracketing assumptions about mental intermediaries). His self-evident first principles relate to reformed epistemology (Plantinga's properly basic beliefs). His libertarian free will engages ongoing debates about determinism, compatibilism, and moral responsibility. His moral intuitionism parallels contemporary ethical intuitionism (Audi, Huemer). His faculty psychology relates to modularity debates in cognitive science. His emphasis on natural beliefs parallels evolutionary epistemology (cognitive capacities evolved for reliability). His skeptical arguments apply to contemporary radical skepticism (brain in vat scenarios). And his moderate realism offers alternative to postmodern anti-realism and naive scientism — trusting ordinary beliefs while acknowledging fallibility.

Reid's common sense principles parallel some Eastern philosophical positions: Confucian emphasis on innate moral knowledge (liang-zhi, innate knowing) resembles Reid's self-evident moral principles. Mencius's argument for innate goodness through universal moral intuitions parallels Reid's conscience as perceiving moral truths. Buddhist epistemology's pratyaksha (direct perception) distinguishes immediate awareness from inference, resembling Reid's direct realism. However, crucial differences: Confucian innate knowledge emphasizes moral cultivation and virtue development; Reid emphasizes rational recognition. Buddhist direct perception aims at liberating insight (prajna), not ordinary perception's reliability. Eastern traditions generally don't appeal to "common sense" as philosophical foundation — they distinguish conventional truth (samvriti-satya) from ultimate truth (paramartha-satya), questioning ordinary beliefs. Reid defends ordinary beliefs; Eastern traditions transcend them. The parallel is structural (immediate awareness, self-evident principles) but Eastern traditions use immediacy for transformation while Reid uses it for justification.