In Steinbeck's words

“Do you take pride in your hurt? Does it make you seem large and tragic? ...Well, think about it. Maybe you're playing a part on a great stage with only yourself as audience.”

“People like you to be something, preferably what they are.” 

“Our species is the only creative species, and it has only one creative instrument, the individual mind and spirit of man. Nothing was ever created by two men. There are no good collaborations, whether in music, in art, in poetry, in mathematics, in philosophy. Once the miracle of creation has taken place, the group can build and extend it, but the group never invents anything. The preciousness lies in the lonely mind of a man.”

“Maybe-- maybe love makes you suspicious and doubting. Is it true that when you love a woman you are never sure-- never sure of her because you aren't sure of yourself? ”

― John Steinbeck, East of Eden

Good vs Evil

“I believe that there is one story in the world, and only one. . . . Humans are caught—in their lives, in their thoughts, in their hungers and ambitions, in their avarice and cruelty, and in their kindness and generosity too—in a net of good and evil. . . . There is no other story. A man, after he has brushed off the dust and chips of his life, will have left only the hard, clean questions: Was it good or was it evil? Have I done well—or ill?” 

John Steinbeck, East of Eden

 

East of Eden (1955), Elia Kazan