What is Theosophy?

Helena Petrovna Blavatsky (1831-1891), née Hahn Von Rottenstern, often known as Madame Blavatsky, was a Russian mystic and author who co-founded the Theosophical Society in 1875. She gained an international following as the primary founder of Theosophy as a belief system.
Blavatsky was a controversial figure during her lifetime, championed by supporters as an enlightened sage and derided as a charlatan by critics. Her Theosophical doctrines influenced the spread of Hindu and Buddhist ideas in the West as well as the development of Western esoteric currents like Ariosophy, Anthroposophy, and the New Age Movement.
She wrote fundamental essays, including Isis Unveiled, The Secret Doctrine, The Key to Theosophy and The Voice of the Silence.
The Blavatsky’s article What is Theosophy?, which we propose to our readers today, was published in October 1879 in The Theosophist.
According to lexicographers, the term theosophia is composed of two Greek words—theos, “god”, and sophos, “wise”. So far, correct. But the explanations that follow are far from giving a clear idea of Theosophy. Webster defines it most originally as “a supposed intercourse with God and superior spirits, and consequent attainment of superhuman knowledge, by physical processes, as by the theurgic operations of some ancient Platonists, or by the chemical processes of the German fire-philosophers”.