Individualist anarchism refers to several traditions of thought within the anarchist movement that emphasize the individual and their will over external determinants such as groups, society, traditions, and ideological systems. Individualist anarchism is not a single philosophy but refers to a group of individualistic philosophies that sometimes are in conflict. Thereafter, it expanded through Europe and the United States. Benjamin R. Tucker, a famous 19th-century individualist anarchist, held that "if the individual has the right to govern himself, all external government is tyranny."