Individual contributors to classical liberalism and political liberalism are associated with philosophers of the Enlightenment. Liberalism as a specifically named ideology begins in the late 18th century as a movement towards self-government and away from aristocracy. It included the ideas of self-determination, the primacy of the individual and the nation as opposed to the state and religion as being the fundamental units of law, politics and economy. Some of these people moved away from liberalism while others espoused other ideologies before turning to liberalism. There are many different views of what constitutes liberalism, and some liberals would feel that some of the people on this list were not true liberals. It is intended to be suggestive rather than exhaustive.
Political philosopher and social psychologist, John Locke was an outspoken supporter of equal rights within a governed society. He was a social contract theorist, believing that the legitimacy of government relies on consent from its citizens which is given on the basis of equality. He supported general toleration of alternative religious beliefs but encouraged the ex-communication of non-believers. Then once a government is established, the role of equality can be analyzed from a social perspective, which is when the idea of religious toleration comes into play. Before there is a government and a nation, man lives in a state of nature where he is guided by the laws of nature as God intended.
The view is not only seen by many commentators as incomplete, but it carries a degree of rationalism that cannot be made consistent with our picture of Locke as the arch-empiricist of his period. For Locke, morality is the one area apart from mathematics wherein human reasoning can attain a level of rational certitude. For Locke, human reason may be weak with regards to our understanding of the natural world and the workings of the human mind, but it is exactly suited for the job of figuring out human moral duty.
Sensibility refers to an acute perception of or responsiveness toward something, such as the emotions of another. This concept emerged in eighteenth-century Britain, and was closely associated with studies of sense perception as the means through which knowledge is gathered. It also became associated with sentimental moral philosophy.