The old Zen saying, «You cannot wash off blood with blood,» refers to the conviction that it is difficult to control thoughts with other thoughts.

This saying implies that the way to control the mind is through the body. In Zen meditation (zazen), this is accomplished through the regulation of breathing and posture. The purpose of this article is to examine the relationship between breathing, posture and concentration in one tradition of Zen. I will explore how this relationship may be relevant to the practice of psychotherapy and the healing arts, as well as its implications for future research in these fields.

http://www.ncbi.nlm.nih.gov/pubmed/22742675

http://www.explorejournal.com/article/S1550-8307(12)00076-6/fulltext