“To allow oneself to be carried away by a multitude of conflicting concerns, to surrender to too many demands, to commit to too many projects, to want to help everyone in everything, is to succumb to the violence of our times,” wrote the wise Trappist monk Thomas Merton in the 1960s, long before the web, or BlackBerrys, or the first use of the word “multitasking” as applied to human activity. “Frenzy destroys our inner capacity for peace.” Were he alive today, he presumably wouldn’t have a Twitter account.