Anarchists hold different views as to the economic and legal organisation of society; some favour collectivist anarchism, anarcho-syndicalism or participatory economics while others support market systems like mutualism, agorism, or anarcho-capitalism. Others, such as anarcho-communists and post left anarchists prefer no solid form of organization. According to The Oxford Companion to Philosophy, "there is no single defining position that all anarchists hold, beyond their rejection of compulsory government, and those considered anarchists at best share a certain family resemblance". Anarchist schools of thought differ fundamentally, supporting anything from extreme individualism to complete collectivism. Some anarchists have opposed coercion, while others have supported it, particularly in the form of violent revolution on the path to anarchy or utopia.