Sri Aurobindo
Letters of Sri Aurobindo
Volume I - Part 2
Fragment ID: 10004
At the time when these chapters [the last chapters of «The Synthesis of Yoga»] were written, the name “overmind” had not been found, so there is no mention of it. What is described in these chapters is the action of the supermind when it descends into the overmind plane and takes up the overmind workings and transforms them1. It was intended in later chapters to show how difficult even this was and how many levels there were between human mind and supermind and how even supermind, descending, could get mixed with the lower action and turned into something that was less than the true Truth. But these later chapters were not written.
1 The highest Supermind or Divine Gnosis existent in itself is something that lies beyond still and quite above.