Conjectural History & the Four Stages of Society

1. Scope and evidence

Established: That Smith, Kames, Millar, Ferguson and others advanced a stadial account of social development organised around four modes of subsistence, and that Dugald Stewart named the underlying method "theoretical or conjectural history," is thoroughly documented in the primary texts and in modern scholarship. Shared / Traditional: The precise number, boundaries and rigidity of the "stages" varied between authors (Ferguson used a three-fold savage/barbarian/polished scheme; some scholars argue Smith used the stages only as a heuristic). The exact status of the theory in Smith's mature Wealth of Nations is actively debated. Disputed / To be handled with care: (1) The method itself was explicitly speculative — "conjectural history" was, by its practitioners' own admission, reasoning about what probably happened in the absence of evidence, not empirical documentary history. This speculative character must be flagged, not smoothed over. (2) The priority question (Turgot vs. the Scots) and (3) the connection to Marx are matters where scholarship counsels caution: the first is treated as independent parallel invention, the second as a loose lineage rather than a proven debt.

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2. Conjectural history as a method

The word for the method arrived after the fact. In his Account of the Life and Writings of Adam Smith, read to the Royal Society of Edinburgh in 1793, Dugald Stewart (1753–1828) — Adam Ferguson's successor at Edinburgh and Smith's first biographer — described and named "theoretical or conjectural history." Stewart's own definition is the classic statement of the method:

> "A few insulated facts may perhaps be collected from the casual observations of travellers, who have viewed the arrangements of rude nations; but nothing … can be obtained in this way, which approaches to a regular and connected detail of human improvement. In this want of direct evidence, we are under a necessity of supplying the place of fact by conjecture; and when we are unable to ascertain how men have actually conducted themselves upon particular occasions, of considering in what manner they are likely to have proceeded, from the principles of their nature, and the circumstances of their external situation."

Three features of the method deserve emphasis. First, it was explicitly speculative: the historian filled gaps in the evidence with reasoned conjecture about how people probably behaved, guided by an assumed uniformity of human nature — what Stewart called "the capacities of the human mind." Second, it was causal and naturalistic, seeking natural causes for social phenomena rather than chronicling particular events; Stewart identified it closely with the French histoire raisonnée and with Hume's Natural History of Religion. Third, it was consciously distinct from documentary history: it was not concerned with high politics, battles and reigns but with the general development of "society" as such — a "moral science." Stewart's own leading example was Smith's essay on the first formation of languages.

Modern scholars have gently noted that Stewart may have had a secondary motive — historian John Burrow argued Stewart wished to insulate the late Smith from the radical political associations of speculative theorising in the anxious 1790s. Either way, the label stuck, and it accurately captures a method whose speculative character its practitioners understood perfectly well. This is the crucial point for honest treatment: conjectural history was philosophy reasoning about probable social development, not archival reconstruction.

3. The four stages explained

At the heart of the tradition lies a deceptively simple idea: the way a society secures its subsistence is the master-key to its whole character — its property system, its laws, its government, its family structure, its manners and morals. As the historian Nicholas B. Miller summarises the "spirit of the paradigm," the fundamental distinguishing features of societies lay "not in accidents of climate, religion or race, but rather in the social, psychological, legal and cultural effects of the history of property and sustenance relations." The clearest single statement is Smith's, from the 1762–63 lecture notes: "There are four distinct states which mankind pass thro:—1st, the Age of Hunters; 2ndly, the Age of Shepherds; 3rdly, the Age of Agriculture; and 4thly, the Age of Commerce."

1. The hunting (and gathering) stage. Subsistence comes from hunting wild animals, fishing and foraging. Population is sparse, property is minimal — essentially confined to what a person carries or immediately consumes — and there is little or no permanent inequality of wealth. On the stadial account, formal government scarcely exists because there is little property to protect; disputes are settled by custom. Smith noted that "an army of hunters can seldom exceed two or three hundred men," because the "precarious subsistence which the chace affords" cannot support larger concentrations.

2. The pastoral (shepherding) stage. With the taming and herding of animals, a durable and movable form of property — livestock — appears. This is a decisive break: for the first time there is significant, unequal, heritable wealth, and with it the emergence of chiefs, dependence and the beginnings of settled authority. Because flocks can support far larger numbers, "an army of shepherds … may sometimes amount to two or three hundred thousand." The Scots repeatedly cited the "Tartars and Arabians" as their model of a shepherd nation. Smith argued that it is precisely here that civil government begins in earnest, to defend the propertied against the propertyless: property and government, in his phrase, "very much depend on one another."

3. The agricultural stage. Settled cultivation of land introduces the most consequential form of property of all: property in land. Land, unlike a herd, is fixed, must be defended over long periods and passed down through generations, and requires a far more elaborate apparatus of law — of tenure, inheritance, contract and courts — to regulate it. Larger, denser, sedentary populations produce durable political institutions; the Scots read European feudalism as a variant of the agricultural stage.

4. The commercial stage. With the growth of towns, manufactures, markets and the division of labour, exchange becomes the organising principle of social life. Property becomes highly mobile and abstract; law becomes correspondingly complex; and individuals, in Smith's account, come to serve the community by pursuing their own welfare through exchange. Eighteenth-century Britain and the commercialising Scottish Lowlands were taken to be examples of this most advanced stage — which the Scots regarded as both the wealthiest and, in important respects, the freest form of society, even as several of them (notably Ferguson) worried about its costs to civic virtue and martial spirit.

The through-line is that a change in the mode of subsistence drives changes in everything else — property, government, law, custom. This is what makes the theory "proto-sociological": institutions are explained functionally, as responses to material conditions, rather than as the gifts of founders or of Providence.

4. Key proponents and texts

Lord Kames (Henry Home, 1696–1782) gave one of the earliest legal applications in Historical Law-Tracts (1758). A judge and man of letters — cousin to Hume and patron to Smith, Millar and Reid — Kames insisted that "law in particular becomes then only a rational study, when it is traced historically, from its first rudiments among savages, through successive changes, to its highest improvements in a civilized society." His "History of Property" tract reconstructs a speculative progression from wandering hunter-gatherers to settled agriculturalists whose need for mutual defence generates law and government. His later Sketches of the History of Man (1774) developed the same historical sociology at greater length. One of Kames's practical aims was to discredit the lingering influence of feudal principles in Scots law — so his Law-Tracts doubled as a manifesto for a modern, commercial Scotland.

Adam Smith (1723–1790) made the four stages an organising structure of his Glasgow Lectures on Jurisprudence, surviving in two sets of student notes — LJ(A) from 1762–63 (discovered in 1958) and LJ(B) relating to 1766 — and published in the modern Glasgow Edition (1978) co-edited by Meek. Smith used the scheme above all to explain the historical evolution of property and government: he illustrated it with a thought-experiment of settlers on an uninhabited island progressing from hunting to commerce, and deployed it to explain military organisation, the origins of property rights, and the development of state revenue. Because Smith ordered his manuscripts burned at his death, the lectures survive only as students' notes; and modern scholars (Berry, Sagar, Paganelli) actively debate how central and how "deterministic" the model really was for him — some reading it as a flexible heuristic rather than a rigid law. (Smith's economic theories proper are treated on later cards; here the focus is the stadial framework itself.)

John Millar (1735–1801), Smith's own student at Glasgow and later Regius Professor of Civil Law there for nearly four decades, produced what modern scholarship widely regards as the most systematic and developed version of the theory in The Origin of the Distinction of Ranks (1771). As Nicholas B. Miller's study John Millar and the Scottish Enlightenment (2017) puts it, Millar "is often cited as the most systematic articulator of the four stages theory." Drawing explicitly on Smith's four stages and on the natural-law division of domestic duties, Millar analysed how progressive economic change transforms authority and social rank across four universal relations — husband over wife, father over children, master over servant, and sovereign over subject. He argued that, with the progress of arts and manufactures, authority tends to become less violent and concentrated, and ranks diversify. His pioneering (if by modern lights still limited) treatment of the historical position of women — tracing the improvement of women's condition as societies advance — is especially noted. Though Millar is not among the three headline figures on this card, Meek regarded him as the central figure of the tradition, writing that Millar's work "seemed to me to be a kind of preview of the materialist conception of history upon which I had been brought up in my revolutionary youth."

Adam Ferguson (1723–1816) deployed a related stadial framework in An Essay on the History of Civil Society (1767), tracking society through savage, barbarous and polished stages and drawing, like the others, on classical authors and contemporary travel literature (he cites Charlevoix on the American Indians). Ferguson's distinctive contribution — his account of civil society, his ambivalence about the division of labour, and his warnings about the corruption of commercial "refinement" — is treated in depth on Card #10; here it is enough to note that his history of society shares the tradition's core method while using a somewhat different stage-vocabulary.

5. The Turgot priority question

Almost exactly as the Scots were developing their theory, the young French statesman-economist Anne-Robert-Jacques Turgot (1727–1781) set out a strikingly similar stadial account. In a Sorbonne discourse of December 1750, A Philosophical Review of the Successive Advances of the Human Mind, and in his roughly contemporary (and unfinished) Plan de deux discours sur l'histoire universelle, Turgot linked agricultural surplus to the growth of towns, arts, the division of labour and inequality — a recognisably four-stage progression from hunting through herding and tillage to commerce.

The obvious question — who got there first? — is one that modern scholarship largely sets aside. The definitive treatment is Ronald Meek's 1971 article "Smith, Turgot, and the 'Four Stages' Theory." Meek's verdict is that the two men almost certainly developed the theory quite independently of one another; he expressly declared his essay to lie "right outside the orbit of the traditional [Turgot–Smith] controversy." Meek regarded the near-simultaneous emergence of the theory in France and Scotland around 1750 as one of the most remarkable coincidences in the history of social and economic thought — a case of multiple, independent invention rather than borrowing in either direction.

The explanation for the coincidence is a shared inheritance rather than mutual influence: the natural-jurisprudence tradition on the origins of property (Pufendorf, Locke), the flood of travel and missionary literature about the North American Indians (Charlevoix, Lafitau) that offered an apparent "laboratory" of early society, and the example of Montesquieu, whom Meek credited as the figure who "pointed out the road" for a naturalistic science of society. A genuine complication is dating: Stewart claimed Smith's lectures "were read at Edinburgh as early as 1748," and some scholars (e.g. Thierry Pauchant) argue Smith's Edinburgh lectures of 1748–51 already contained an early version. But the hard textual evidence for the full four-stage scheme that early is contested — Meek himself later retracted a passage in which he had wrongly back-dated it, on the advice of Andrew Skinner — and the securely dated, explicit statement is the 1762–63 Glasgow lecture. A further caution: Turgot's stadial writings were largely unpublished and unfinished in his lifetime, surviving through later editions (Daire, 1844; Schelle, 1913–23), so the comparison is between texts of quite different documentary status. As Leo Steeds observed in 2025, the authorship and priority issue, "unless new materials are discovered, may never be resolved definitively." The current scholarly consensus, accordingly, is that priority is essentially unresolvable and largely beside the point: the theory was, in Meek's account, an inevitable next step from Montesquieu, "made multiply and independently by Smith, Turgot, Kames, and others."

6. Purpose and significance — and the Marx question

The stadial theory was, above all, an alternative mode of historical explanation. Against the providential universal histories in the tradition of Bossuet, which organised the human past around divine design and a succession of religious epochs, it substituted secular, material causes. Against the older habit of explaining institutions as the deliberate creations of great lawgivers — a Lycurgus, a Solon, a Romulus — it argued that laws and governments grow out of changing modes of subsistence. And against the conventional narrative history of kings and battles, it proposed a history of society, property and manners. This is why the tradition is so often called the seedbed of modern social science: it treated society as an object of causal, comparative, generalising inquiry.

The parallel with Karl Marx's later materialism is real and frequently noted — but it should be stated carefully. What Smith and Turgot called the "mode of subsistence," Marx would rename the "mode of production," and both traditions share the idea that the material base shapes the legal and political "superstructure," that government is derivative from property relations, and that history proceeds through a succession of qualitatively distinct social formations. Marx and Engels certainly read and admired the Scottish political economists. But the honest scholarly position is that this represents a looser intellectual lineage and a notable parallel, not a fully documented, point-by-point causal debt. Marx's stages (ancient, feudal, bourgeois…) are different from the Scots' four; his driving mechanism (class conflict and the contradiction between forces and relations of production) is his own; and — as scholars note — the Scots never really solved the dynamics of transition between stages, which is precisely where Marx concentrated. Meek, a Marxist economist, was drawn to the Scots as a "preview" of historical materialism; but "preview" is the appropriate register — anticipation and affinity rather than proven descent. The claim should be made with hedging, not asserted as a strong causal thesis.

7. Critiques and limitations — examined honestly

Per this site's "accuracy over patriotism" standard, the theory's genuine defects deserve a full airing rather than a footnote.

It was speculative by design. As already stressed, "conjectural history" filled evidential gaps with reasoned guesswork. At its best (as Anthony Brewer has argued of Smith) this meant interpreting incomplete evidence as any historian must; at its worst it meant confident narratives about a human past for which there was, and often still is, no direct record. Some of Kames's reconstructions — for instance, of property emerging only with settled agriculture — are now simply known to be wrong: property relations, contracts and enforcement systems appear in the very earliest written records (Sumerian and Akkadian law), long predating anything the Scots imagined as the dawn of "civil" society.

It was teleological and Eurocentric. The four stages were not offered as morally neutral descriptions but as a ladder of improvement culminating in contemporary European commercial society, which was treated as the pinnacle and effective end-point of a single, universal developmental sequence. As Nicholas B. Miller notes, "in taking the commercial society of eighteenth-century Britain as the pinnacle of the history of liberty, postcolonial scholars have, with validity, critiqued it as a blatant example of Eurocentric world historical narration." The same schema was turned inward on Scotland itself: Highlanders were routinely cast as a people "stuck" in an earlier, "ruder" stage than their Lowland neighbours — the historian William Robertson wrote that, in the Highlands and Islands, "society still appears in its rudest and most imperfect form."

It treated indigenous peoples as "living fossils." The theory's most serious problem, by modern standards, is methodological and ethical at once. Lacking evidence of Europe's own deep past, the conjectural historians treated contemporary non-European peoples — above all Native Americans — as living specimens of the earlier stages through which Europe had supposedly already passed. Locke had already written that "in the beginning all the world was America"; the Scots systematised the assumption. This is the central theme of Ronald Meek's Social Science and the Ignoble Savage (1976), whose very title makes the point: alongside the familiar Romantic "noble savage," Enlightenment social science generated an "ignoble savage" — the primitive not as innocent but as backward, a data-point in a European story of progress. Meek showed that reports of American Indian societies (via Charlevoix and Lafitau) were the "empirical rock" on which the theory was built.

Modern anthropology has thoroughly repudiated this "comparative method" of reading present-day societies as time-capsules of others' pasts. It assumes a single universal developmental track; it denies that the peoples so classified have histories of their own; it flattens enormous cultural diversity into a European stage-scheme; and — as the entwining of stadial theory with emerging racial science in the later 18th century shows (recent work on "Scottish medical ethnography" traces exactly this drift) — it helped furnish an intellectual vocabulary that could rationalise colonial dispossession, from Locke's property theory onward. None of this means the Scots were uniquely malicious: many held, against the racial theorists then gaining ground, to a belief in the common humanity and equal rationality of all peoples, and some (Ferguson, Smith) wrote critically of slavery and empire. But the framework's colonial-era assumptions are a real and significant limitation, and any account that celebrated the theory's originality while ignoring them would be dishonest.

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