Dawsey writes to Juliet that according to Adelaide Addison, having fun is the worst sin. He explains that during the war, there were few eligible local men and the ones around were scraggly. The Germans, on the other hand, were glamorous and rich. Some women dated Germans in order to feed their families. Dawsey says that others befriended the Germans because they were bored. Some people thought that greeting Germans was conspiring with the enemy, but Dawsey found that Christian Hellman was a good man.
Dawsey's willingness to understand that people became friends with the Germans for a variety of reasons shows that he believes that all people are multifaceted and complex; while some of the Germans may have been terrible, it's clear that plenty of others were kind, at least to women who agreed to sleep with them.
By late 1941, there was no salt. The Germans decided to get salt for everyone by boiling seawater. This plan failed, as there wasn't enough wood to boil the water away, so people started cooking soups in seawater. Dawsey noticed that there were people who couldn't haul buckets home, so he acquired a pram and two wine casks and began carrying water to those who couldn't fetch it themselves. One November day, Christian helped Dawsey lift one full barrel and then helped him lug the second up the cliff. They dropped it and somehow found it funny.
Notice that in the case of the Germans' plan to get salt, they devise a plan that will help both themselves and the islanders. This suggests that not everything about their occupation was unfeeling and cruel, even if the system they came up with couldn't actually serve everyone effectively.
Christian noticed that Dawsey dropped his Charles Lamb book and mentioned that he loved the author. As they parted, Dawsey offered to let Christian borrow a book and with that, they became friends. Christian often helped Dawsey carry water and they'd talk. Dawsey soon discovered that Christian and Elizabeth knew each other. In early 1942, the Germans sent Christian to work in a hospital, but his ship sank. Dawsey marvels that Charles Lamb helped him find friends like Juliet and Christian.
When Dawsey attributes his friendships with Juliet and with Christian to Charles Lamb, it shows that Dawsey believes that literature has the power to connect people despite living miles apart or vastly differing political ideologies. In other words, it helps him to humanize both of his friends, as their love of Lamb helps Dawsey see that they have feelings and care for others.