In the Spiritual Exercises of St. Ignatius, A.M.D.G. means the moment of decision after one has searched one's soul trying to make a difficult choice. When faced with these difficult choices, St. Ignatius directs his readers, one should make one's decision based on which option will be "for the greater glory of God." To use this expression as a dedication in a book or on a building, Ong asserts, is inappropriate, for no particular decision has been made. It is sufficient to pronounce that the book or building exists simply "for the glory of God," without the addition of the word "greater."
Nevertheless, there are times when St. Ignatius used A.M.D.G. to discuss
the process he used to make decisions, the results of which were converted
into procedures for others to follow. In these cases, Ong believes
that St. Ignatius used the phrase in a manner similar to that of current
usage because his decisions were public proclamations. If the phrase
must be used in a dedicatory fashion as it now is, people should at least
remember and acknowledge St. Ignatius' use of the phrase to mean a soul-searching
process that can lead to a public proclamation.