Positive liberty is the possession of the power and resources to act in the context of the structural limitations of the broader society which impacts a person's ability to act, as opposed to negative liberty, which is freedom from external restraint on one's actions. The concepts of structure and agency are central to the concept of positive liberty because in order to be free, a person should be free from inhibitions of the social structure in carrying out their ambitions. Structurally, classism, sexism, ageism, ableism and racism can inhibit a person's freedom. As positive liberty is primarily concerned with the possession of sociological agency, it is enhanced by the ability of citizens to participate in government and have their voices, interests, and concerns recognized and acted upon. Isaiah Berlin's essay "Two Concepts of Liberty" (1958) is typically acknowledged as the first to explicitly draw the distinction between positive and negative liberty. Charles Taylor works to resolve one of the issues that separate ‘positive’ and ‘negative’ theories of freedom, as these have been distinguished in Isaiah Berlin's seminal essay, ‘Two concepts of liberty'. He sees it as undeniable that there are two such families of conceptions of political freedom. Thus, Taylor clarifies that there are two competing theories. One aims to define freedom exclusively in terms of the independence of the individual from interference by others, be these governments, corporations, or private persons; this theory is challenged by those who believe that freedom resides at least in part in collective control over the common life. Negative liberty is a concept that is often used in political philosophy. It is the idea that freedom means being able to do what you want, without any external obstacles. This concept has been criticized for being too simplistic and not taking into account the importance of individual self-realization. Taylor suggests that negative liberty is little more than a philosophical term and that real liberty is achieved when significant social and economic inequalities are also considered.