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.