Nietzsche, Maeterlinck, Strindberg, and Tolstoy, the four great authors discussed in this book stand, respectively, for the determining strains in a great upsetting movement, and that in the aggregate they bring to view the composite mental and moral impulsion of the times. They are, one and all, radicals in thought, and, with differing strength of intention, reformers of society, inasmuch as their speculations and aspirations are relevant to practical problems of living.