▁goal ▁of ▁Christian ▁per fection , ▁said ▁Mother ▁Ter esa . ▁" Hol iness ▁is ▁impossible ▁without ▁it ." ▁Ign ati us ▁of ▁Lo y ola , ▁the ▁Church ' s ▁patron ▁of ▁retre ats , ▁popular ized ▁med itation ▁and ▁cont empl ation ▁through ▁his ▁thirty - day ▁retre at ▁or ▁Spirit ual ▁Ex er cis es , ▁which ▁he ▁custom arily ▁admin ister ed ▁to ▁lay pers ons . ▁ ▁Nature ▁and ▁history ▁ ▁M ental ▁prayer ▁was ▁defined ▁by ▁John ▁Hard on ▁as ▁a ▁" form ▁of ▁prayer ▁in ▁which ▁the ▁sent iments ▁expressed ▁are ▁one ' s ▁own ▁and ▁not ▁those ▁of ▁another ▁person . ▁M ental ▁prayer ▁is ▁accomplished ▁by ▁internal ▁acts ▁of ▁the ▁mind ▁and ▁aff e ctions ▁and ▁is ▁either ▁simple ▁med itation ▁or ▁cont empl ation ." ▁ ▁P ray er ▁is ▁mental ▁when ▁the ▁thoughts ▁and ▁aff e ctions ▁of ▁the ▁soul ▁are ▁not ▁expressed ▁in ▁a ▁previously ▁determined ▁formula . ▁The ▁function ▁of ▁mental ▁prayer ▁is ▁to ▁transform ▁the ▁mind ▁and ▁thereby ▁effect ▁a ▁change ▁in ▁dispos itions ▁and ▁in ▁the ▁heart . ▁Such ▁transformation ▁is ▁a ▁lif el ong ▁process . ▁Ad ol phe ▁Tan qu ere y ▁distingu ishes ▁between ▁vocal ▁prayer , ▁which ▁is ▁expressed ▁by ▁words ▁or ▁gest ures , ▁and ▁mental ▁prayer ▁" which ▁takes ▁place ▁wh olly ▁within ▁the ▁soul ." ▁M ental ▁prayer ▁can ▁proceed ▁by ▁using ▁vocal ▁pray ers ▁in ▁order ▁to ▁improve ▁dialog ue ▁with ▁God . ▁M ental ▁prayer ▁can ▁be ▁divided ▁into