Chapter 13 continues on with Steinbeck’s reflections about the nature of man.  His summations are encapsulated in this statement:  “And this I believe:  that the free, exploring mind of the individual human is the most valuable thing in the world.”

That free mind can also be dangerous.  Steinbeck narrator turns his gaze on the situation at the Trask home.  He considers how and why Adam is able to delude himself so about Cathy’s true nature.  It is that creative mind at work, a force so powerful that it can shape things and rationalize behavior in whatever way it deems fit.  Adam does not see Cathy’s lack of affection, his brother’s anger, because he has created Cathy in his image:  “a sweet and holy girl.”

Adam comes home one day to find Cathy “nearly dead from loss of blood.”  The doctor is summoned.  He discovers that Cathy had tried to abort her pregnancy with a knitting needle.  Adam does not know she is pregnant.  She did not succeed.  The doctor tells her that if she tries it again, he will testify against her.

Cathy claims that she is afraid to have a baby because of possible epilepsy.  The doctor softens and says he will not tell Adam.  Adam’s dream life explodes.  He envisions creating a dynasty for his family.  He buys a lush plot of land.  He never asks Cathy her opinion and imagines she is as enthusiastic as he. 

Here the lives of the Trasks and Hamiltons finally cross.  Adam hires Samuel to improve his land.