Sri Aurobindo
Letters of Sri Aurobindo
Volume II - Part 1
Silence is always good; but I do not mean by quietness of mind entire silence. I mean a mind free from disturbance and trouble, 
steady, light and glad so as to be open to the Force that will change the nature. The important thing is to get rid of the habit of the invasion of troubling thoughts, wrong feelings, confusion of ideas, unhappy movements. These disturb the nature and cloud it and make it more difficult for the Force to work; when the mind is quiet and at peace, the Force can work more easily. It should be possible to see things that have to be changed in you without being upset or depressed; the change is the more easily done.