Source : Webster's Revised Unabridged Dictionary (1913)

Theosophy \The*os"o*phy\, n. [Gr. ? knowledge of things divine,
   fr. ? wise in the things of God; ? God + ? wise: cf. F.
   th['e]osophie.]
   Any system of philosophy or mysticism which proposes to
   attain intercourse with God and superior spirits, and
   consequent superhuman knowledge, by physical processes, as by
   the theurgic operations of some ancient Platonists, or by the
   chemical processes of the German fire philosophers; also, a
   direct, as distinguished from a revealed, knowledge of God,
   supposed to be attained by extraordinary illumination;
   especially, a direct insight into the processes of the divine
   mind, and the interior relations of the divine nature.

Source : WordNet®

theosophy
     n : belief based on mystical insight into the nature of God and
         the soul