'Brutus' refers to the pseudonym used by an anonymous author of a series of essays opposing the ratification of the U.S. Constitution in the late 18th century. These essays, particularly Brutus I, expressed concerns about the potential for a strong central government to infringe on individual liberties and states' rights, which contrasted sharply with the arguments presented in Federalist No. 10 advocating for a large republic to control factions. The writings of Brutus are significant in understanding the debates surrounding the formation of the U.S. government and the balance between federal and state powers.