5., 1897); and in his popular lectures, Das Wesen des Christentums appeared in 1900 (5th ed., 1901; English translation, What is Christianity? 1901).
5., 1897); dan pada 1900 muncullah kuliah-kuliahnya yang populer, Das Wesen des Christentums (edisi ke-5, 1901; terj. bahasa Inggris, What is Christianity? 1901).