Stillness does not mean a peaceful mind, for a peaceful mind is something and stillness in no-thing. The mind can be temporarily calm but this is not stillness. Once we have awakened to the stillness beyond the mind, the latter will cease to be agitated, it will be reduced to its function, that is to movement. Stillness is not in the slightest way affected by this movement. It is inaccurate to say that in stillness there is no longer mind-function. It is the nature of the mind to move although there may be spontaneous moments of non-movement when the mind is suspended in wonder, astonishment or admiration or any unexpected appearance that finds no reference to previous experience, or the moment after a desired object is obtained. Function and non-function belong to the mind but they appear and disappear in stillness which not a function.
Agitation is produced by desire, the desire of the individual me to bring an end to its isolation, its separation from its origin. In its distress it tries every imaginable means to create pleasure and security. It ultimately longs for joy. Though moments of pleasure and satisfaction are reflections of ultimate fulfillment they remain conditioned by time and space. They are temporary and there is always the fear that loneliness and emptiness will return.
Once the ego sees that it only seeks what it already knows, that its desires are conditioned and that its true desire is for permanent security and tranquility, it loses its dynamism to find itself in phenomenal things. Then what is behind the desire, the ego, the mind, is revealed. We are left in wonder and all dispersed activity dissolves in this wonderment.
– Jean Klein
From I Am, page 117
You can read more from Jean Klein here.