In his last years, Scriabin realized a noble and great idea. Inspired by his study of theosophical writings, he dreamed of joining music, poetry, mime, architecture, light, color and even aromas to create a Gesamtkunstwerk, and thus elevate human beings to a higher level of consciousness. This Mysterium was never completed, but his late piano sonatas-conceived as preliminary studies-enable us to see what moved Scriabin. He spent a particularly long time working on his eighth sonata and proofread it intensively; but later quite a few mistakes still found their way into it. Thanks to the autograph and the first edition, ambiguous passages have now been cleared up and corrected in our Urtext edition.