The historical and comparative method is the practice of explaining a social arrangement by asking two linked questions: how does it differ from the same arrangement elsewhere, and how did it come to be what it is? Comparison supplies variation across cases; history supplies variation across time. The two are treated as one method because the sociologist who compares societies almost always compares them at particular moments in their development, and the sociologist who traces a society's past is implicitly comparing its successive states.
Its rationale is negative and decisive. Sociology cannot put societies in a laboratory, randomise treatments or rerun a revolution with one variable altered. What it can do is locate cases that resemble one another in many respects and differ in the one that interests the researcher, and treat that natural variation as an approximation to experimental control. This is why the method has always been regarded as the discipline's methodological core rather than as one technique among many.
Durkheim: comparison in place of experiment
Émile Durkheim made the argument explicit in The Rules of Sociological Method. Since the sociologist cannot produce phenomena at will, indirect experiment — that is, comparison — is the only proof procedure available, and sociology is therefore comparative by nature. Of the forms of comparison Durkheim regarded the method of concomitant variation as the instrument par excellence: rather than hunting for cases where a factor is simply present or absent, the researcher establishes that two phenomena vary together in a regular series, which is far better evidence of a causal bond than a handful of matched instances.
He attached rules to this. Comparison is legitimate only within the same social species, so that societies of comparable type and scale are set against one another; the researcher must compare a phenomenon across the whole range of societies in which it occurs, not select convenient instances; and only one cause should be admitted for one effect, Durkheim rejecting the doctrine of plurality of causes. Suicide is the demonstration: rates set against religious confession, marital status and political circumstance, across regions and periods, yielding integration and regulation as the explanatory variables.
Weber: comparison to establish the particular
Max Weber's use of comparison had the opposite emphasis. Where Durkheim compared to find general laws, Weber compared to isolate what was distinctive about a single historical outcome — the rise of rational capitalism in the West. His sociology of religion accordingly ranged across Protestantism, Confucianism and Taoism, Hinduism and Buddhism, and ancient Judaism, asking in each case what the religion's ethic implied for economic conduct in the world. In The Religion of India he argued that the combination of caste, karma and ritual obligation channelled religious energy away from the systematic rational transformation of worldly activity — an interpretation extensively criticised since, but methodologically instructive.
Weber's comparison worked through the ideal type, a deliberately one-sided construct against which real cases are measured and found to deviate, and through counterfactual reasoning about what would have followed had a condition been absent. His aim was causal adequacy for a particular configuration, not a universal law.
Mill's logic, and its difficulties
The underlying logic was codified by John Stuart Mill. The method of agreement examines cases sharing an outcome and looks for the single antecedent they have in common. The method of difference compares cases alike in most respects where the outcome occurs in some and not others, and identifies the antecedent that varies with it. Concomitant variation handles factors that come in degrees rather than in presence and absence.
Mill himself doubted that these could work on societies, and his doubts have proved durable. Social causes are typically multiple and conjunctural, so the same outcome may arise by different routes; the number of macro-level cases is small while the number of plausible causes is large, so the evidence rarely determines a single explanation; and cases are not independent of one another. Galton's problem names this last difficulty: if two societies share a trait because one borrowed it from the other, or both received it from a third, the apparent correlation records diffusion, not a functional or causal connection. Colonial transmission of law, bureaucracy, education and census categories across Asia and Africa makes this a live concern for any comparison of formerly colonised societies.
Sources and their treatment
Historical sociology works with materials it did not create. Archives yield administrative correspondence, revenue and settlement records, judicial proceedings, census and gazetteer volumes, missionary and company papers. Institutional records — inscriptions, land deeds, temple accounts, guild and union registers, company ledgers — document practice rather than pronouncement. Oral history and folklore reach communities the written record ignored, which for Dalit, adivasi and women's histories is often the only route available, at the cost of the well-known frailties of memory.
Three problems recur. Source survival is not random: records survive because someone with power kept them, so the archive is systematically biased towards the literate, the propertied and the state, and silence in the record is not evidence of absence. Reliability requires the ordinary discipline of the historian — establishing authorship, purpose, audience and internal consistency, and reading official categories as artefacts of administration rather than as neutral descriptions. Anachronism is the third: importing present-day categories into periods that did not possess them, or reading a later outcome back into earlier events as though it had been intended.
Indian historical sociology
The Indian tradition shows the method's power. Bernard Cohn urged sociologists and historians to read each other's sources and demonstrated, in essays collected as An Anthropologist among the Historians (1987), how colonial administrative practice — settlement operations, the census, the codification of custom — produced the very social categories later scholars treated as timeless. A. R. Desai's Social Background of Indian Nationalism (1948) explained nationalism through the material transformations of the colonial economy. D. D. Kosambi's reading of Indian history combined textual, archaeological and ethnographic evidence to argue about the formation of caste from the absorption of tribes into an agrarian order. Studies of the Mughal agrarian system and of regional agrarian change since have supplied the long-run backdrop against which village studies of the 1950s become legible.
For the UPSC answer
State the rationale first: comparison is sociology's substitute for the experiment that it cannot perform. Then contrast Durkheim and Weber sharply — Durkheim comparing within a social species to establish general laws, with concomitant variation as his favoured instrument, Weber comparing world religions to explain a unique Western outcome through ideal types. Bring in Mill's methods of agreement and difference as the underlying logic and Galton's problem of diffusion as its most serious limitation, alongside source survival, reliability and anachronism. Close with Cohn on colonial categories or Desai on nationalism, which shows the method doing Indian work rather than merely European work.
References & further reading
- Mill, J. S. (1843). A System of Logic, Ratiocinative and Inductive. John W. Parker.
- Durkheim, É. (1895). The Rules of Sociological Method.
- Weber, M. (1916–17). The Religion of India: The Sociology of Hinduism and Buddhism.
- Skocpol, T. (1979). States and Social Revolutions. Cambridge University Press.
- Tilly, C. (1984). Big Structures, Large Processes, Huge Comparisons. Russell Sage Foundation.
- Cohn, B. S. (1987). An Anthropologist among the Historians and Other Essays. Oxford University Press.