Maybe we all have in us a secret pond where evil and ugly things germinate and grow strong. But this culture is fenced, and the swimming brood climbs up only to fall back. Might it not be that in the dark pools of some men the evil grows strong enough to wriggle over the fence and swim free? Would not such a man be our monster, and are we not related to him in our hidden water? 

In this quotation, which appears in Chapter 13, Section 2, the novel’s narrator contemplates the nature of evil and man’s relationship to it. Through this metaphor of black water, he suggests that everyone has the capacity for evil within them. The ability to contain that darkness is what ultimately makes the difference between a man and a monster. This concept emphasizes that evil is not a force that humankind can eradicate in its entirety but one that goodness must fight to keep at bay.

“He was a liar and a hypocrite too.” Kate spat out her words. “That’s what I hate, the liars, and they’re all liars. That’s what it is. I love to show them up. I love to rub their noses in their own nastiness.” Adam’s brows went up. “Do you mean that in the whole world there’s only evil and folly?” “That’s exactly what I mean.”

In Chapter 25, Section 3, Adam visits Cathy for the first time since she abandoned him and their sons, and he struggles to understand why she harbors so much resentment toward everyone and everything in the world around her. This quotation reveals her belief that she is surrounded by liars, a position which drives her to commit her own horrible sins with little regard for their consequences. Rejecting goodness altogether becomes a kind of defense mechanism for Cathy as it prevents her from feeling the pain of an internal moral struggle.

And then Lee’s mind played on the way it often did. Suppose it were true—Adam, the most rigidly honest man it was possible to find, living all his life on stolen money. Lee laughed to himself—now this second will, and Aron, whose purity was a little on the self-indulgent side, living all his life on the profits from a whorehouse. 

In Chapter 53, Section 2, Adam finally acknowledges that his father, a man who lied incessantly about his war experience to gain wealth and status, was a thief. While this recognition is a major step forward for Adam, the significance of this quotation comes from the way in which Steinbeck highlights man’s capacity to simultaneously indulge both good and evil. Two separate generations of upstanding Trask men have ironically become entangled in morally corrupt inheritances. This dynamic challenges the notion that good and evil have a binary relationship.