Aristotle labours under no illusion that in the practical sphere humans operate according to the canons of logic. This does not prevent him, however, from bringing his own logical acumen to his study of human behaviour. Aristotle, according to Fr. Flannery, depicts the way in which human acts of various sorts and in various combinations determine the logical structure of moral character. Some moral characters--or character types--manage to incorporate a high degree of practical consistency; others incorporate less, without forfeiting their basic orientation towards the good. Still others...