PRESENTATION COPY. – Helena Petrovna BLAVATSKY. The Key to Theosophy. London: The Theosophical Publishing Company, Limited, [1889.] Inscribed in ink on the title-page ‘With the author’s compliments’, 8vo (208 x 161mm.) Title, ‘Preface’, 14pp. publisher’s advertisements to rear. (Browned to margins, lacking half-title.) Original blue cloth with the Theosophical seal, the gilt ouroboros, Seal of Solomon, the Ankh and the Om, and gilt lettering to upper cover (wear to spine ends and upper joint, inner hinge slightly weakened). Note: written towards the end of her life, Blavatsky used a question and answer format to expound upon the foundational principles of Theosophy. It not being, for example, a conventional religion but an attempt to unite humanity under common principles of brotherhood and ancient truths that have shaped human thought. Provenance: The Aquarian Book Service (ink stamp to title).