East of Eden: Novel Summary: Part III Chapter 23 – 26

 Chapters 23 -26
Part III begins in 1911 with a summary of the Hamilton Family. Una, Samuels favorite, married a photographer and moved to Oregon where her dispassionate husband starved her. Samuels guilt over Unas ill-treatment casts him into a depression from which he never emerges. He ages quickly and his children are shocked at his decline. They cook up a plan to have their parents come to visit them, ostensibly as a vacation but really so they can care for them. Samuel knows what they are up to but accepts nevertheless. 
Samuel visits Adam before he leaves and once again meets the twins he delivered, now eleven years old. Immediately, the story of Cain and Abel comes to mind. When Lee brings drinks, the three men take up their conversation of the Cain and Abel story and the philosopher Lee explains he has in the interim been studying the story with four aged Chinese gentlemen and a rabbi in San Francisco. One translation of the Bible maintains that God promises Cain that he will overcome sin, but another translation says God orders Cain to overcome sin. After years of research, the men happily come to the conclusion that the correct translation is neither, and that the Hebrew word, timshel, the verb causing the discrepancy, actually means “thou mayest.” Lee beams in satisfaction when Samuel comes to fully grasp the meaning: God gave human beings the freedom to choose goodness over evil. At this point, Samuel makes a choice in an effort to help his friend Adam and tells him Cathy, now known as Kate, is still in Salinas and runs a notorious whorehouse. Adam, unable to stand the pain, runs away in horror.
Adam attends Samuels funeral and afterwards gets drunk and goes to see Kate.  He sees her not as a beautiful woman, but as a monster and feels free for the first time in years. She tempts him sexually and shows him photos of powerful men in sexually compromising situations, and becomes hysterical when he fails to respond.
Kate throws one last weapon at Adam by telling him he might not be the childrens father, but Adam says it doesnt matter.
Adam decides to buy a car from Samuels son Will. At home he tells Lee about Kate. Lee asks Adam to allow him to fulfill his dream of establishing a bookstore. 
The biblical Cain and Abel story is central to the novel, as is the exegesis of the Hebrew word timshel. Although the novel is filled with the presence of evil, humans have the power to overcome it. A tragic destiny is decreed for no one; it is all a matter of human choice. In these chapters, Adam at last shows an ability to recognize Cathy for who she is. In order to choose good over evil, evil must first be recognized.