What lesson on perspective was Edwin trying to teach Cole?

In Chapter Seven, the theme of anger again plays a central role. Edwin and Cole go to the stream, and Edwin declares that they will go swimming in a freezing pond to teach Cole a lesson. He makes Cole dip completely into the water shoulder-high and then asks him to break a stick, whose left side represents anger and right side represents happiness. In this lesson, anger is personified in multiple forms. It is present in the exercise at the freezing pond where Edwin uses a stick as a symbol of the futility of fighting anger. Just as Cole must accept the numbness caused by the freezing water, he must accept his own anger.