They therefore devoted themselves to examining the nature of the soul, and taught that its freedom consists in communion with God, to be achieved by absorption in a sort of ecstatic trance. This doctrine reached its height with Plotinus; later followers emphasized theurgy in its unsuccessful combat with Christianity. Finally this pagan theosophy was driven from Alexandria back to Athens under Plutarch of Athens and Proclus, and occupied itself largely in commentaries based mainly on the attempt to re-organize ancient philosophy in conformity with the system of Plotinus.