Divine simplicity is the idea that, as the ultimate principle of the universe, God must be a non-composite unity not made up of parts or diverse attributes. The idea was appropriated by early Christian theologians from non-Christian philosophy and played a pivotal role in the development of Christian thought. Andrew Radde-Gallwitz charts the progress of the idea of divine simplicity from the second through the fourth centuries, with particular attention to Basil of Caesarea and Gregory of Nyssa, two of the most subtle writers on this topic, both instrumental in the construction of the Trinitar