The eighteenth century was a period of dramatic change in political and legal thought. Much of the way in which we currently conceive of democratic institutions and the responsibilities and rights attached to citizenship can be traced back to concepts that dominated eighteenth-century thought. The social contract was debated by figures such as John Locke, Algernon Sidney, David Hume, Edmund Burke, and Mary Wollstonecraft. Among the many issues under deliberation were the validity of consent, the will of individuals, the role of virtue, and the rights of self-governance. Legal thought was very closely tied to political thought because law was a foundation of political authority. Natural law, which was associated with divinity, rose in importance because it protected inalienable rights, such as self-preservation. Positive law, that is, laws of civil society such as common law and statute law, could be reformed and updated as civil society evolved. This flexibility was praised by jurists such as Lord Mansfield, but it also drew attempts to clarify and systematize law by Sir William Blackstone and Jeremy Bentham, as they prepared the citizenry for a growing engagement with the law.