In positivist sociology, a social fact is an abstraction external to the individual which constrains that individual's actions. Law is an example, the suicide rate in a given community another. The term was coined by 19th century French sociologist Emile Durkheim, and was crucial to Durkheim's analysis of society (and to that of his followers) but is little used today.
Where Auguste Comte dreamed of making sociology an all-encompassing discipline that contained all others—'the queen of sciences', in his terms— Durkheim was less ambitious. Durkheim aimed to set sociology on a firm, positivist footing, as a science among other sciences. He reasoned that any particular science must have unique subject matter which is not shared with any other science, but which must be capable of investigation by empirical means. Variations within the phenomena under investigation, according to Durkheim, must be explained by causes which also lie within the realm of that particular science. In consequence, Durkheim asserted that sociology must become the 'science of social facts'.
In his 1895 manifesto Rules of Sociological Method, Durkheim wrote: "A social fact is every way of acting, fixed or not, capable of exercising on the individual an influence, or an external constraint; or again, every way of acting which is general throughout a given society, while at the same time existing in its own right independent of its individual manifestations."
In Durkheim's view, sociology was simply 'the science of social facts'. The task of the sociologist, then, was to search for correlations between social facts and thus reveal laws. Having discovered the laws of social structure, the sociologist is then able to determine if any given society is 'healthy' or 'pathological' and prescribe appropriate remedies.
Durkheim's work on the 'social fact' of suicide rates is famous. By carefully examining police suicide statistics in different districts, Durkheim was able to 'demonstrate' that Catholic communities have a lower suicide rate than Protestants, and ascribe this to a social (as opposed to individual) cause. This was groundbreaking work and remains much-cited even today. Initially, Durkheim's 'discovery of social facts' was seen as significant because it promised to make it possible to study the behaviour of entire societies, rather than just of particular individuals. Modern sociologists refer to Durkheim's studies for two quite different purposes, however: