To assume the rôle of critic and to compare Spengler’s with other philosophies of the present phase of Germany, as to respective intrinsic weights, is not the purpose of this note nor within the competence of its writer. On the other hand, it is unconditionally necessary for the reader to realize that the book before him has not only acquired this large following amongst thoughtful laymen, but has forced the attention and taxed the scholarship of every branch of the learned world. Theologians, historians, scientists, art critics—all saw the challenge, and each brought his _apparatus criticus_ to bear on that part of the Spengler theory that affected his own domain. The reader who is familiar with German may be referred to Manfred Schroeter’s “Der Streit um Spengler” for details; it will suffice here to say that Schroeter’s index of critics’ names contains some 400 entries. These critics are not only, or even principally, general reviewers, most of them being specialists of high standing. It is, to say the least, remarkable that a volcanically assertive philosophy of history, visibly popular and produced under a catchy title (Reklamtitel) should call forth, as it did, a special number of _Logos_ in which the Olympians of scholarship passed judgment on every inaccuracy or unsupported statement that they could detect. (These were in fact numerous in the first edition and the author has corrected or modified them in detail in the new edition, from which this translation has been done. But it should be emphasized that the author has not, in this second edition, receded in any essentials from the standpoint taken up in the first.)