THIS book which more properly titled, Philosophy of the Christian Religion, was written by Andrew Martin Fairbairn and may be described as an attempt to do two things : first, to explain religion through nature and man; and, secondly, to construe Christianity through religion. The author conceives religion to be a joint product of the mind within man and the nature around him, the mind being the source of the ideas which constitute its soul, the nature around determining the usages and customs which build up its body.