The father of the Karamazov brothers is a disgusting sensualist. He has virtually no redeeming qualities. He is a self-centered man — corrupt and immoral — and is cynically dedicated only to the fulfillment of his bestial appetites. He has married twice for selfish reasons and has treated each wife with total disrespect. Little wonder, for a man who has no respect for himself can respect no one else.
As is pointed out during Dmitri's trial, he was never, in the truest sense, a father to any of his sons. When they were young, he was oblivious to their presence and relieved when relatives took them away. Later, he refused to give any of them money, and although the matter is not stated definitely in the novel, all indications suggest that he cheated Dmitri out of a large portion of his mother's inheritance.
Fyodor's vulgarity is part and parcel of his every action; he lives the part of the vulgar buffoon, delighting in embarrassing anyone in his presence. Not surprisingly, his degeneration leads indirectly to his death; it was his seduction of the village idiot, "stinking Lizaveta," that produced Smerdyakov, the strange epileptic who grew up as his father's servant and then dispassionately slaughtered him.