Importance of the heart in the spirituality of mankind

“The heart directs the entire organism, and when grace gains possession of the heart, it reigns over all the thoughts and all the members, for it is there, in the heart, that the mind and all the thoughts of the soul have their seat” (Macarius the Egyptian. [1964]. Hom. XV 20, PGXXIV, 589B, ed. H. Dörries, p. 139).