  If, as Rosmini suggests, ontology is the ‘theory of abstract being’, rational theology is the ‘theory of subsistent Being’. These two parts of theosophy cannot, however, can be distinguished only if the same universal concepts, of which both are formed, can in some way be differentiated. This is done by considering that ontology serves to find, review, and describe the nature and relationship of these concepts; theology, in Rosmini’s understanding, synthesises them to form a single concept of the infinite Being. It is true that such a concept remains abstract (the essence contained in the concept is not beheld by the knowing subject), but the ‘theologian’ passes from the concept to affirm subsistent Being, which is therefore no longer a mere concept, but something which must exist in itself. An effort is then made in rational theology to see how the ontological concepts have their truth and their foundation in first subsistent Being. While this takes place, the concepts themselves are identified and become one. Their separation, now considered anew, is seen to be relative not to first subsistent Being, but to the beholding, finite mind. The problem of the One and the many is rooted not in the nature of absolute, subsistent Being, but in being by participation.