Criticism of libertarianism includes ethical, economic, environmental and pragmatic concerns and is often focused on right-libertarianism. Critics have argued that laissez-faire capitalism does not necessarily produce the best or most efficient outcome, and that libertarianism's philosophy of individualism and policies of deregulation fail to prevent the abuse of natural resources. Criticism of left-libertarianism is instead mainly related to anarchism and includes allegations of utopianism, tacit authoritarianism and vandalism towards feats of civilization. Left and right-libertarians also engage in criticism of each other. Ethical criticism Aggression and coercion The validity of right-libertarian notions of liberty and economic freedom have been questioned by critics such as Robert Lee Hale, who posits that laissez-faire capitalism is a system of aggressive coercion and restriction by property owners against others: Adam Smith's "obvious and simple system of natural liberty" is not a system of liberty at all, but a complicated network of restraints, imposed in part by individuals, but very largely by the government itself at the behest of others on the freedom of the "some". ... What in fact distinguishes this counterfeit system of "laissez-faire" (the market) from paternalism, is not the absence of restraint, but the absence of any conscious purpose of the part of the officials who administer the restraint, and of any responsibility or unanimity on the part of the numerous owners at whose discretion the restraint is administered. Other critics, including John Rawls in Justice as Fairness, argue that implied social contracts justify government actions that violate the rights of some individuals as they are beneficial for society overall. This concept is related to philosophical collectivism as opposed to individualism. In response, libertarian philosophers such as Michael Huemer have raised criticisms of the social contract theory. Authenticity of libertarian goals Critics such as Corey Robin describe right-libertarianism as fundamentally a reactionary conservative ideology united with more traditional conservative thought and goals by a desire to enforce hierarchical power and social relations: Conservatism, then, is not a commitment to limited government and liberty—or a wariness of change, a belief in evolutionary reform, or a politics of virtue. These may be the byproducts of conservatism, one or more of its historically specific and ever-changing modes of expression. But they are not its animating purpose. Neither is conservatism a makeshift fusion of capitalists, Christians, and warriors, for that fusion is impelled by a more elemental force—the opposition to the liberation of men and