The German Lebensphilosophie—or “philosophy of life”—was less a coherent school than a diffuse intellectual current. Its origins lay partly in response to the crisis of nineteenth-century academic philosophy, yet its influence extended beyond the university into broader cultural debates of the early twentieth century. This borderline position between scholarly discourse and cultural criticism was reinforced by Lebensphilosophie’s refusal to define its central concept, “life.” Precisely because “life,” as life-philosophers stated, resisted conceptual elaboration, the movement could encompass under a shared banner numerous intellectual, artistic, and spiritual tendencies diverging from biologism to mysticism. 

In his essay “The Conflict in Modern Culture,” Georg Simmel, himself a prominent representative of Lebensphilosophie, retrospectively observed that around 1900, “life” had emerged as the dominant philosophical motive of the age, comparable in status to “being” in ancient Greece or “God” in the Christian Middle Ages. Like those earlier guiding ideas, it expressed what Simmel called the “secret being” of an epoch. His observation is at once an analysis of the movement and a self-articulation from within it. It is, therefore, revealing that Simmel himself acknowledged that “life,” unlike its predecessors, appeared as a reactive concept, a polemical counter to what was perceived as dead or hostile in modern civilization. “Life” became the criterion of cultural criticism: everything was to be judged before the “tribunal of life,” in Nietzsche’s phrase, and measured by whether it promoted vitality, creativity, and immediacy—or stifled them. In this capacity, Lebensphilosophie resonated with parallel movements, including the youth movement, neo-Romanticism, the Lamarckian revival, and educational reform. It was thus not an organized doctrine, but a generational stance, articulated with tools adopted from professionalized academic philosophy, which both voiced and shaped the anxieties of fin-de-siècle German culture.