The book provides a presentation and analysis of the philosophy of life and its history, from its beginnings with Nietzsche, Dilthey, and Bergson to its peaks with Simmel, Th. Lessing, Klages, Spengler, and Ortega y Gasset. It features the voices of its interpreters, particularly Scheler, Misch, and Bollnow, as well as critics like Rickert and Lukács. The fact that life philosophical approaches are still being received in the 21st century is primarily due to a broad ecological thinking, but also to the continuation of life philosophical ideas by Michel Henry in his radical life phenomenology.