Isis Unveiled, published in 1877, is a book of esoteric philosophy, and was Helena Petrovna Blavatsky's first major work. It is composed of two volumes, the first concentrating on science, and the second on religion. The two volumes support the idea of spirituality and theosophize in accordance with it. Blavatsky herself distinguishes between spiritual phenomena and Spiritualism, the religious system. She supports the verity of spiritual phenomena, not the views of the Spiritualists, which she wrote about extensively in such works as The Key to Theosophy. The volume on science attempts to show how science can be just as dogmatic as religion, and betrays its own scientific method by denying spiritual phenomena with no scientific proof against it, meanwhile citing various scientists of renown that have acknowledged the necessity of a spiritual reality. The volume on religion attempts to expose the hypocrisy of certain established religions by focusing on how and where they have strayed from their origins and worked counter-actively, while simultaneously tracing the doctrines of the most revered mystics and philosophers to a common spiritual root.