By definition, liberals are individuals who accord primacy to liberty as a political value. One way that liberals accord primacy to liberty is through their strand of popular thought advocated by Locke, which asserts that "humans are naturally in a state of perfect freedom to their actions,... as they think fit,... without asking leave or depending on the will of any other man" (Gaus and Cortland, 2011).Secondly, liberals assert that any restrictions on liberty should be justified. The liberal idea of freedom however does not constitute a unitary concept. Instead, in the contemporary liberal political thinking there exist divergent conceptions of freedom including the negative concept of freedom and the positive concept of freedom.
Recent liberal thinking such as John Rawls, Joel Feinberg, and Stanley Benn hold the apriori view in favor of freedom that was advocated by Locke. This strand of thought, further debated by Mill, asserts that the burden of proof regarding prohibition or restriction of freedom rests with those individuals who are against liberty (McGowan, 2007, p. 42). This is regarded as the fundamental liberal principle which holds freedom as a normative basic with the onus of justification for denial of an individual's freedom placed on those intending to limit individual's freedom, especially where coercion is used as happens with law and political authority (Starr, 2008, p. 31).. Protection of individual's freedom according to this view requires that law and political authority are justified. This led to the advocacy of the social contract theory as developed by among others John Locke, Thomas Hobbes and Jean-Jacques, which recognizes that humans are free and equal and only the social contract should justify any limitation to the enjoyment of these freedoms (Gaus and Cortland, 2011).
Besides liberal holding that any restrictions on liberty must be justified such as through the social contract theory, another strand of thought espoused by Hobbes asserts that drastic limitations of liberty can be justified (Gaus and Cortland, 2011). Locke's liberal view however held that fairly modest limitations should exists leading to the support of the assertion that only limited government can be justified. This view was also shared by Rawls who asserted through his first principle of justice that, "...each person is to have an equal right to the most extensive system of equal basic liberty compatible with a similar system for all" (Gaus and Cortland, 2011). While liberals agree about the extent for limitations of liberty, the disagreements about what constitutes liberty (concept of freedom) has led to different conceptions of government roles. The disagreements on the idea of liberty (freedom) among liberals are varied.
One idea of freedom held by liberals asserts that an individual experiences freedom to the extent or degree that no man or body of men interferes with his or her activities (Gaus and Cortland, 2011). This view, advocated by Isaiah Berlin is referred to as the negative conception of liberty. Freedom in this sense entails acting within an area without obstructions by others. In a scenario where others prevent an individual from doing whatever they intend to do, then to an extent the person is regarded as not free to a certain degree. This view holds that an individual lacks freedom where there is deliberate interference from other human beings on what the individual can do or cannot do and the spheres within which the individual can act. Lack of freedom in this sense entails some sense of coercion or some degree of enslavement, which is lack of freedom. Liberals who hold similar view as advocated by Berlin regard freedom as absence of coercion. The view has been regarded as an opportunity concept, which recognizes being free as merely a matter of what an individual can do, the options that are open to an individual regardless of whether an individual decides to exercise these options or not (Gaus and Cortland, 2011).
A divergent strand of idea on what constitutes freedom to an individual is the concept of positive liberty. This view, which has attracted many liberals was advocated by among others Rousseau and late nineteenth and early twentieth century British neo-Hegelians such as Bernard Bosanquet and Thomas Hill (Gaus and Cortland, 2011). The view as advocated by Rousseau asserts that an individual is only free when one acted according to his or her true will (Gaus and Cortland, 2011). While Green acknowledges the view that an individual is not free when under compulsion from another individual or body of individuals, he also asserted that an individual is also not free when he or she is subject to cravings or impulses that he or she cannot control (Bellamy, 2005, p. 40). Such an individual according to positive freedom view does not carry his or her own wish but the will of others. Only when an individual is autonomous and self directed could he or she be regarded as free according to positive view of freedom. This liberal view of freedom further claims that an individual, is only free only when his actions are his or hers. This has led to the positive concept of freedom being regarded as an exercise concept (Gaus and Cortland, 2011).
The positive idea of freedom thus posits that only to the extent which one is able to shape their life is one free. Such an individual is not subject to compulsions. Such an individual also is able to critically reflect his or her ideals instead of unreflectively following the set traditions and customs. An individual who is free under the positive concept also does not ignore his or her long term interest for the sake of short term pleasures. The positive view of freedom is now recognized as the most common among liberals. While it has its roots in Kants, Rouseau and John Stuart Mill it is recently evident in work of Benn, Gerald Dworkin, Christmas and Anderson, and Joseph Raz.
A different strand of positive freedom regard freedom as the effective power to pursue ones end or to act in a particular way (Gaus and Cortland, 2011). This has been regarded as the "ability act". This free of freedom, may for instance be shown where an individual may wish to join a members only club but due to poverty, he is unable to join such a club since membership is very costly or unaffordable. Such an individual is not free according to this strain of positive freedom. This results from the inability of the individual to act due to poverty. Such a concept of freedom definitely impacts on policy proposed by liberalist holding such an idea of freedom. For instance, this may require that policies are formulate that will require that education is readily available to ensure that individual develop their capacities for earnings in future.
Finally, liberals may hold the republican idea of liberty. The idea freedom in this strand of thought is that one is not free when they are exposed to the idiosyncratic judgments of other persons (Gaus and Cortland, 2011). Freedom entails not living in servitude or domination. In order to ensure freedom under this idea of freedom, power is a crucial factor and the concept asserts that government should ensure that no agent, even itself should give itself arbitrary power over citizens. The meaning of freedom among liberals differs markedly. These differences in the idea of what constitutes freedom has implications on the policies that liberal would advocate. This has led to confusion even when all agree on the basic tenet of liberty as the primacy of the liberals' views.