Spiritual psychology has a special status and essential role in philosophical theology of Thomas Aquinas and Mulla Sadra. Characteristics of such status and role can be clearly found in compiling structure of “Summa Theologiae” of Aquinas and “Asfar” of Sadra. A Comparative survey of this fundamental element in two systematical structures indicates that these philosophers has so similarly regarded spiritual psychology in networks of metaphysical teachings and doctrines that considered both ontological aspect of human being as caused/creature and his epistemological statue or situation about God, himself and world. But the issue of the way of human beings toward God in two mentioned systems has provided two different types of justification and compiling structure, because of different Christian background of Aquinas’ thought and Islamic background of Sadra's thought.