ALLY, 1. this is a noun which means an individual who cooperates with, supports and helps another for a common object; a supporter, a friend. In Dn and Scn, it basically means someone who protects a person who is in a weak state and becomes a very strong influence over the person. The weaker person, such as a child, even partakes the characteristics of the ally so that one may find that a person who has, for instance, a bad leg, has it because a protector or ally in his youth had a bad leg. The word is from French and Latin and means to bind together. (LRH Def. Notes) 2. by ally in Scn, we mean a person from whom sympathy came when the preclear was ill or injured. If the ally came to the preclear’s defense or his words and/or actions were aligned with the individual’s survival, the reactive mind gives that ally the status of always being right–especially if this ally was obtained during a highly painful engram. (HCOB 20 Mar 70)
ALLY COMPUTATION, little more than a mere idiot calculation that anyone who is a friend can be kept a friend only by approximating the conditions wherein the friendship was realized. It is a computation on the basis that one can only be safe in the vicinity of certain people and that one can only be in the vicinity of certain people by being sick or crazy or poor and generally disabled. (DMSMH, p. 243)
Hubbard, L. R., (1975) Dianetics and Scientology Technical Dictionary, Los Angeles: Church of Scientology of California Publications Organization.