Hegeler rejected dualism as an unscientific and untenable view and accepted monism upon the basis of exact science, and for the discussion of the more recondite and heavier problems of science and religion he founded a quarterly, The Monist, in October 1890.
The Great Apostasy is a term used by some religious groups to describe a perceived fallen state of traditional Christianity, especially the Roman Catholic Church, because they claim it allowed the traditional Greco-Roman mysteries and deities of solar monism such as Mithras and Sol Invictus and idol worship into the church.
In essence, the philosophy of Achintya bheda abheda, or "inconceivable oneness and difference", avoids the extremes of Shankara's monistic Advaita vedanta and Madhva's pure dualism (Dvaita) by interpreting the material and spiritual potencies of the Supreme Person (Bhagavan) as being simultaneously one and different with Him.