The vast majority of soldiers are loathe to kill in battle. Unfortunately, modern armies, using Pavlovian and operant conditioning, have developed sophisticated ways of overcoming this intinctive aversion. The psychological cost for soldiers, as witnessed by the increase in post-traumatic stress, is devastating. The psychological cost for the rest of us is even more so: contemporary civilian society, particularly the media, replicates the army's conditioning techniques and, according to Grossman's controversial thesis, is responsible for our rising rate of murder, especially among the young.