In The Chrysalids, there are two books owned by David's grandfather, Elias, to form the basis of this dystopian society. The first is the Bible, and the second is called Repentances, authored by Nicholson. The former, of course, exists, but my research shows no real book entitled Repentances, which seems to be a book invented by Wyndham for the purposes of his tale. The Bible is used for the proposition that man was created in God's image; thus anything or anyone who was somehow deviant must be ungodly and banished or killed. The Repentances contains a series of "commandments." These are displayed prominently in the Strorm household and include "KEEP PURE THE STOCK OF THE LORD" (18) and "WATCH THOU FOR THE MUTANT" (18). These commandments and a selective reading of the Bible create a society, which, in the aftermath of what appears to have been some sort of nuclear war or accident, is obsessed with rooting out any possible mutation or difference in animals, plants, or people, no matter how unimportant the difference is. David, for example, is concerned even about being left-handed, and when he comes to understand that he is able to communicate with others with his mind, he realizes that this is a mutation of even greater concern, one that finally forces him to flee from his community.