The reflections offered here have properly to do with the theology of the Holy Trinity rather than with the Trinity itself; their purpose is to consider how we advance in our theological understanding of the revelation of the Holy Trinity communicated to us by Scripture and Tradition, by pointing to those movements of our spp iritual life which are especially relevant to our theological understanding of the faith. St Augustine, in the later books of his de Trinitate, was the first to dopt this procedure explicitly; and his has been the determining influence in all Latin theology after him. But the later theology so much took his Preliminary investigations for granted that it is not easy for the reader of a moderm dogmatic treatise dealing with the Holy Trinityto understand the truly religious and spiritual interest of the theology of the Trinity: he may admire the technical Ingenuity of the solutions proposed, the sustained intellectual effort and the scrupulous integrity required to present within manageable limits the essential Catholic doctrines, but he may fail to enter with a quick sympathy into the inner life of such and investigation.