Against the dominant sociological methods of his time, Simmel argued that sociology should be the study of forms — the recurring shapes that social interaction assumes regardless of what fills them. Conflict between nations and conflict between colleagues share a form. The stranger in a medieval village and the stranger in a modern city share a form. The dyad of lovers and the dyad of business partners share a form. Formal sociology isolates these shapes and investigates their structural properties. The power of the method is that the forms travel: insights about the stranger in 1908 Berlin apply to the AI collaborator in 2026, because the formal position is the same. The limitation is equally consequential: formal analysis describes the geometry of social life without providing a compass for navigating within it.
Simmel distinguished his approach from both the historicism of Weber and the functionalism of Durkheim. Where Weber sought to understand the specific historical constellation that produced modern capitalism, and Durkheim sought the functional contributions of institutions to social order, Simmel sought the formal invariants — the shapes that persist across every historical period, every cultural context, every specific content.
The method's power lies in its formal precision. The stranger is defined by the unity of nearness and remoteness, not by any particular historical content. The dyad is defined by its structural dependence on both members' continued participation, not by any particular relationship. Fashion is defined by its dialectic of imitation and distinction, not by any particular style. These formal definitions enable the concepts to migrate across historical periods with a fidelity that content-bound analyses cannot achieve.
The limitation is the structural counterpart. Formal analysis identifies the shape of social interaction but does not specify what should fill the shape or how it should be filled. Simmel's analyses consistently arrive at the recognition that the same process produces both liberation and constraint, both expansion and impoverishment. This ambivalence is analytically precise — it captures the genuine complexity of modernity's effects — but it provides no basis for choosing between the opposed tendencies it identifies. The formal sociology describes the geometry with extraordinary precision. It does not offer a compass.
The application to AI inherits both the strength and the limitation. The framework illuminates the AI moment with insights no technology-first analysis could produce: the stranger's position, the tragedy of culture, the dyad without fragility, the door that has been crossed. But the framework cannot decide, on formal grounds alone, how much weight to place on the stranger's contributions, what institutional forms would restore productive conflict without sacrificing collaborative efficiency, or which thresholds should be maintained and which should be dissolved. The practical wisdom required to act within the geometry must come from elsewhere.
Simmel articulated the formal method across his career, most systematically in the introductory chapter of the 1908 Soziologie. The method became one of three major founding approaches in sociology — alongside Weber's interpretive sociology and Durkheim's positivist sociology — and shaped the Chicago School through Robert Park and Ernest Burgess, both of whom studied with Simmel in Berlin.
The method's portability has made it uniquely useful for analyzing historical transformations Simmel could not have anticipated. Its limitations have been most pressed by Marxist and feminist critics, who argue that attention to form without attention to power reproduces the existing distribution of advantage.
Form versus content. Sociology's proper object is the recurring shapes of interaction, not the specific historical materials that fill them.
Structural invariance. Formal properties persist across historical contexts — the stranger in one era and the stranger in another share a structural position regardless of the specific content of the strangeness.
Analytical precision. The method produces insights that travel, because the formal definitions are not bound to any particular historical content.
Relative inattention to power. The framework describes shapes without systematically asking who benefits from a particular shape and who is disadvantaged by it — a limitation sharpened by the AI application.
Geometry without compass. Formal analysis identifies structural features without specifying what should be done about them; practical wisdom must come from elsewhere.
Marxist critics argue the formal method naturalizes existing power relations by treating them as structural invariants rather than historical products subject to transformation. Feminist critics have raised similar concerns about the method's relative silence on gender. Defenders respond that formal analysis is not exhaustive — it is one tool among several — and that its specific strengths complement rather than replace the analyses it cannot provide.