 Both schools of thought also had a great deal to say about the Return, which was viewed in two respects: compulsory and voluntary. From the standpoint of the compulsory Return, the cosmos unfolds following its own ineluctable laws, and human beings go back to God in a series of stages that mirror the stages of cosmogenesis. From the standpoint of the voluntary Return, free will allows human beings to play a role in determining the trajectory of their own becoming. To a certain degree they are co-creators of their own souls and the posthumous realms, which are experienced in karmic terms, that is, as the result of a chain of causality set in motion by their own individual understandings, character traits, and activities. Ibn ‘Arabî marks a watershed in the discussion of both sorts of Return, not least because his explications of the mundus imaginalis allowed him to provide rational arguments for issues like bodily resurrection that, according to Avicenna, could not be understood by reason but can only be accepted on the basis of faith (Avicenna, al-Shifâ’, 347–48; Avicenna, al-Najât, 3:291). Ibn ‘Arabî’s leads were expanded on by later thinkers, most exhaustively by Mullâ Sadrâ in the fourth book of his magnum opus, al-Asfâr al-arba‘a, on the topic of the soul and its unfolding (Mullâ Sadrâ 2008).