Why does Sethe attack Mr. Bodwin and let Beloved disappear again?

To Sethe, who at this point in the novel, is close to being consumed by the physical manifestation of her guilt and sorrow, the arrival of Mr. Bodwin triggers the pivotal memory of the arrival of Schoolteacher and his boys all those years before that led to the tragedy of her life. In her confusion, Sethe projects Schoolteacher's intentions upon poor innocent Mr. Bodwin and tries to kill him. The focus of her rage and violence on the perceived perpetrator this time, instead of on her innocent children like before, serves to absolve Sethe of her guilt and release her from the haunting of her dead child.