“ These exercises are concerned with practice, not with understanding. You do not need to practice what you already understand. It would indeed be circular to aim at understanding, and assume that you have it already.
It is difficult for the untrained mind to believe that what it seems to picture is not there. This idea can be quite disturbing, and may meet with active resistance in any number of forms. Yet that does not preclude applying it. No more than that is required for these or any other exercises. ”