The volume contains two of Simmel's most significant monographs: "Main Problems of Philosophy," published in 1910 as a jubilee volume in the Göschen collection, which became one of the highest-circulation scientific publications of the time, and "Philosophical Culture," a highly regarded collection of masterful essays to this day. For Simmel, "Philosophical Culture" was not just a title, but a program. Philosophical culture does not consist in the knowledge of metaphysical systems or the adherence to individual theories, but in a consistent intellectual attitude towards all existence, in an intellectual dynamism directed towards the layer where, in various depths and connected to a multitude of circumstances, all possible lines of philosophy converge.