Nine volumes are expected to be published in the series of collected work of F.Hausdorff. Up to now, Volume II (Grundzüge der Mengenlehre), Volume IV (Analysis, Algebra und Zahlentheorie) and Volume VII have been published. The first 85 pages of Volume VII are devoted to the analysis of Hausdorff's philosophical work, orientation and letters, from the years around 1900. Then, several of Hausdorff's philosophical publications, written under the pseudonym Paul Mongré, are included. The first one is “Sant' Ilario. Gedanken aus der Landschaft Zarathustras” (almost 400 pages, published in 1897), continued by “Das Chaos in kosmischer Auslese” (more than 300 pages, published in 1898). The volume ends with three shorter essays (5-6 pages) from 1900-1902: “Nietzsches Wiederkunft des Gleichen”, “Nietzsches Lehre von der Wiederkunft des Gleichen” and “Der Wille zur Macht”. An index of names is added at the very end.