Helena Petrovna Blavatsky (Russian: 12 August [O.S. 31 July] 1831 – 8 May 1891) was a controversial Russian occultist, philosopher, and author who co-founded the Theosophical Society in 1875. Blavatsky was the leading theoretician of the Theosophical Society, responsible for establishing its "doctrinal basis".The ideas expounded in her published texts provide the basis from which the Society and wider Theosophical movement emerged. Blavatsky's Theosophical ideas were a form of Occultism. She subscribed to the anti-Christian current of thought within Western esotericism which emphasized the idea of an ancient and universal "occult science" that should be revived.Blavatsky stated that the Theosophical teachings were passed on to her by adepts, who lived in various parts of the world.