We sometimes mistake rest for the absence of activity. But I find that my deepest rest comes from those times when I intensify my activity. I can do this by becoming completely engrossed in a physically demanding challenge (primitive hunting, free-diving, hand-to-hand combat), or by becoming totally absorbed in the solitude of reflection and prayer. The key words of the previous sentence are these adverbs: completely, totally. The important point is that rest does not come from the absence of a particular activity; it comes from an absolute change of soul-centered engagement.