One of the most important texts to be encountered in this wonderful novel is the Psalter or copy of the Psalms that Jacob bears with him into Japan, even though being found with it would be enough to get him into serious trouble as no copies of any texts that are considered subversive and dangerous (such as religious texts) are allowed into the compound and to enter Japan, which is presented as a closed nation to the Westerners that land there. This Psalter is of course important to Jacob not through its religious significance, but through the way that it functions as something of a good-luck charm to himself and to his family. He is unable to simply burn it because of the way in which he was given it by his father. Jacob is a character therefore who is placed in danger very early in the novel because of his possession of this text and his refusal to destroy it.
Another text which is of great importance is The Wealth of Nations, by Adam Smith. The importance of this book lies in its espousal of free market econimics and the way in which this should be the model of economics for the future. As this book is being read in Japan, which, at the time, was a closed country where trade was only allowed to occur under very strict and stringent guidelines, there is a massive irony as the traders are forced to struggle with any number of aspects that prevent "free" trade from occurring, such as translators who act against them and spy on them and officials and upper class members of Japanese society who do everything they can to control the presence of the foreigners among them.