Selflessness
I have listened to the first eight sessions of the CSS foundations course, and am enjoying it very much. Besides the Byron Katie audios, there are not many I am drawn to listening to in this way.
Joel points out that there are really no "neutral" activities in terms of spiritual practice. Either, they reinforce (exercise) selfishness, or they move in the direction of selflessness.
And these terms are taken literally here. Selfishness is the belief in an "I" or the "story of I", and everything that brings with it. Selflessness is the realization that there really is no "I" anywhere, and what comes out of that.