What is a summary of Chapter 4 of The Winter of Our Discontent by John Steinbeck?

Chapter 4 takes place on Holy Saturday, the day between Good Friday and Easter.  Almost all of the chapter takes place at the grocery store, where Ethan has a series of conversations with other people:

• his wife Mary, before he leaves for work


• Stonewall Jackson Smith, the cop


• Joey Morphy, who works at the bank next door


• Margie Young-Hunt, who flirts with him


• Mr. Baker, the banker


• Marullo, Ethan's boss


• the salesman who has already offered Ethan a bribe


• and Mary, his wife, again, this time on the phone

This is not counting the long speech that Ethan gives to the groceries when no one else is around. 

In each of these conversations, we see foreshadowing of the transformation that Ethan is preparing to go through.  For example, with Stonewall Jackson and with Joey Morphy, Ethan discusses a bank robbery (something he will later attempt). To Stonewall Jackson, Ethan also mentions his childhood friend Danny Taylor, now a pitiful drunk, whom Ethan will later betray in order to get his family's land. In talking to the groceries, Ethan discusses how people can mentally prepare themselves to do things they know are wrong, how his ancestors got their money through piracy (rationalized as patriotism), and how all money, if you keep it long enough, becomes respectable. When talking to the salesman who earlier tried to bribe him, Ethan still turns him down, but this time with words ambiguous enough to make the man think he is actually bargaining for a bigger kickback. 

Ethan begins the chapter talking about his Aunt Deborah, who instilled in him a fresh and immediate belief in Jesus' death and resurrection. He also recalls a time when he mentally consulted his grandfather, the Cap'n, for strength to do something difficult, and the Cap'n gave it to him. This is the person that Ethan has been until now: reverent, upright, willing to do the hard thing even though it may not benefit him, and filled with love and respect for his older relatives and the morals they taught him.  

But in the rest of the chapter, we see him laying the groundwork so that he can become a very different person: deceptive, conniving, willing to use other people in order to get himself some money and status in the world. He is ready to learn not from his upright ancestors, but from the cynical Joey, the corrupt Baker, and the salesman. He will become like them and beat them at their own game.

The perceptive Margie notices that Ethan doesn't "seem like the same man. ... What caused it?" Ethan responds, "Maybe I'm sick of being a grocery clerk."