Proclus (c. 410 - 485) was one of the major Greek philosophers of late Antiquity. In his metaphysics he developed and systematized problems of Plato's thought, such as participation, transcendence - immanence, causation - participation - return, henads and monads, first and second causality. Before and after his works had been translated into Latin, Proclus influenced the Christian West through the Liber the causis ("Book of Causes"), a Latin translation of an anonymous Arab version of Proclus' Elementatio theologica.