The two sons of Squire Cass, Godfrey and Dunstan (Dunsey) are known by way of their father, who is a respectable and relatively wealthy man in comparison with the rest of the people of Raveloe. As children of an upper-class home, the two grew up in idleness from what the narrator tells us. Yet, out of the two sons, the highest hope is laid on Godfrey, the eldest of the two sons, who is described as
a fine, open-faced good-natured young man
Godfrey seems to appear to the public as the gentler, kinder, and nicer of the two brothers, only these days the townsfolk agreed that
Mr. Godfrey didn't look half so fresh-colored and open as he used to do.
The suspicion is that Godfrey is following the steps of his wayward brother, Dunsey, who is quite possibly his exact opposite, making them an allusion to Cane and Abel. Dunstan's influence in Godfrey has made the latter change
...the good-humored, affectionate-hearted Godfrey Cass was fast becoming a bitter man, visited by cruel wishes
Although Godfrey does enjoy more respect than his brother, we find that he is weak of character, prone to being misled, and easily fooled. The evidence of this lies in that Gofrey now drinks and covers up for his brother's wrongdoings. To make matters worse Godfrey married a laudanum addicted woman, fathered a child with her, and is trying his best to hide the truth from his father.
Godfrey's physique contrasts with his lack of character. He is also described as lacking resolution, and of being morally coward.
That big, muscular frame of his held plenty of animal courage, but helped him to no decision when the dangers to be braved were such as could neither be knocked down nor throttled.
Dunstan Cass is described with more negatively than Godfrey. Physically, he is described as
a thick-set, heavy-looking young man entered, with the flushed face and the gratuitously elated bearing which mark the first stage of intoxication.
Dunstan, is the leader of the two. He is arrogant, senseless and selfish. He is also younger than Godfrey, who is twenty-six years old. In terms of his behavior he is more lose and daring than Godfrey; Eliot also says that Dunstan is intellectually dull in comparison. It is clear that Dunstan holds a lot of contempt against Godfrey, and it is evident in the way that the speaks to him disrespectfully despite of him being his older brother. The bad marriage choice that Godfrey made was like fuel for Dunstan, who obviously tries to bring his brother down to his level.
His overall character is described as "spiteful" and "jeering", with a taste for swapping and betting and with obvious disregard for the well-being or safety of others, especially his brother.
Godfrey and Dunstan are actually quite different. However, Dunstan's presence and influence on Godfrey is what brings out Godfrey's negative traits at the beginning of the novel. Once Dunstan is out of the picture, things become better for his elder brother.