Gershom Carmichael was a teacher and writer who played an important role in the Scottish enlightenment of the eighteenth century. His philosophy focused on the natural rights of individuals--the natural right to defend oneself, to own the property on which one has labored, and to services contracted for with others. Carmichael argued that slavery is incompatible with the rights of men and citizens, and he believed that subjects have the right to resist rulers who exceed the limits of their powers. Although he appealed to the authority of Grotius and Locke, the grounds on which he defended natural rights were distinctively his own. He drew upon the Reformed or Presbyterian theology to propose that, in respecting the natural rights of individuals, one shows one's reverence for God's creation. Inasmuch as all of mankind longs for lasting happiness, which can be found only in worship of or reverence for God, such reverence is the natural law which obliges all to respect the rights of all.