This paper inquires into the aspects of violence and principles of thought which trigger such violence in Toni Morrison’s Beloved. As Morrison’s novel represents ambiguity of good and evil while it demonstrates explicit and implicit violence, this paper focuses on Sethe’s equivocal position as an assailant and a victim of violence. This paper first explores Sethe as the object of violence by two white masters, Mr. Garner and the School Teacher. The cruel violence toward her by the School Teacher is incurred by the dichotomous thought principle which underlies the institutional violence of slavery. Mr. Garner’s attitude toward violence and the underlying thought principle is elaborated upon in the light of the concept of ‘sheer thoughtlessness’ by Hannah Arendt. Meanwhile, the aspect of violence incurred by black community triggered by envy and anger is explored with the concepts of ‘intentional ignorance’ and ‘negligence’ by Thomas Aquinas. Next, Seth as the instigator of violence and her murder of Beloved is discussed. The thought principles underlying the violent act of the infanticide are dual: protection of Sethe’s freedom and subjectivity as a human being and rescue of Beloved from the future life as a slave. Through the analysis of the aspects of violence and the thought principles in Beloved, the paper ultimately argues that Morrison’s novel reexamines ethical dilemma which confronts humanity. The novel urges the reader to reevaluate the violence imbedded in dichotomous thinking, sheer thoughtlessness and intentional ignorance and negligence in thought, while continuing to “rememorying” and mourning as the last sentences in the novel resonate: “It was not a story to pass on. It was not a story to pass on. This is not a story to pass on.”