Sri Aurobindo
Letters of Sri Aurobindo
Volume IV - Part 4
The purpose they [the hostile forces] serve in the world is to 
give a full chance to the possibilities of the Inconscience and Ignorance – for this world was meant to be a working out of these possibilities with the supramental harmonisation as its eventual outcome. The life, the work developing here in the Asram has to deal with the world problem and had therefore to meet, it could not avoid, the conflict with the working of the hostile Powers in the human being.