Generally, Chasidic discourses by the Chabad leaders are based on a verse of the written Torah, or a saying of the sages, that provides a point of departure for a self-contained, reasoned discussion of G-dly knowledge. Human spirituality and soul-powers are investigated in great depth and detail, to advance the human mind in the knowledge of G-d and facilitate an emotional relationship reflected in love and fear and the fulfillment of mitzvot.The discourses in Torah Or and Likkutei Torah do not exhaust the treasury bequeathed by the Alter Rebbe. In 5738 (1978) the Lubavitcher Rebbe gave instructions that the thousands of discourses remaining in manuscript be edited and printed by Kehot Publication Society. Twenty-four volumes have appeared, most with extensive references to earlier sources and later Chasidic discourses, as well as overviews, indexes and more.