Why is Thomas Putnam such a bitter man?
In Act One, Miller gives the reader some background information on certain characters, including Thomas Putnam. His brother-in-law, James Bayley had been a viable candidate to be minister of Salem. He had two-thirds of the vote and all of the qualifications, but some faction blocked him, and the position went to a man named Burroughs.
Putnam is the oldest son of the richest man in Salem. This alone makes him think he is superior to everyone else. So, when his candidate (Bayley) doesn't get the position, he is offended. Putnam has fought Indians in battle and makes it a point to be involved in church affairs. Because Putnam thinks so highly of himself in these ways, whenever people don't bend to his will, he retaliates and/or feels like he deserves more than he's been given. Regarding this episode of losing the position of minister, Putnam feels that his family name has been denigrated.
He is also bitter because a large portion of his father's estate had gone to his step-brother. Putnam tried to fight this, but failed. Putnam feels superior because of his family's heritage (money). He has grown into a bitter, greedy man who takes whatever opportunity he can to increase his estate, wealth, and prestige in the village. Of course, he primarily values prestige in terms of wealth.