1. a Greek word suggesting a “climb” or “ascent” upwards. The anagogical is a method of spiritual interpretation of literal statements or events, especially the Scriptures.
Certain Medieval Theologians describe four methods of interpreting the Scriptures: literal/historical, allegorical, tropological (moral), and anagogical. Hugh of St. Victor, in De scripturis et scriptoribus sacris, distinguished anagoge from allegory. The latter is when a visible fact is signified by another visible fact. Anagoge, on the other hand, is ‘leading above,’ when by a visible fact an invisible is declared.
2. The spiritual or mystical interpretation of a word or passage beyond the literal, allegorical or moral sense (especially in Biblical criticism).
Source: Wikipedia. Or the Ancient Greeks depending on what you mean by source.