Dietrich Bonhoeffer was able to work with concentration. He did whatever work had to be done without hesitation. Yet this ability was accompanied by a willingness to be interrupted, and even a craving for company when playing music. He loved chess, bridge, and guessing games, and demanded the same competiveness of his fellow players, but he always gave his opponents the benefit of the doubt. 

~ Eberhard Bethge, Dietrich Bonhoeffer: A Biography (Revised Edition); Portrait (1970), xviii.