The Essays is commonly considered Kames's most important philosophical work. In the first part, he sets forth the principles and foundations of morality and justice, attacking Hume's moral skepticism and addressing the controversial issue of the freedom of human will. In the second part, Kames focuses on questions of metaphysics and epistemology to offer a natural theology in which the authority of the external senses is an important basis for belief in the Deity. Henry Home, Lord Kames (1696-1782) was one of the leaders of the Scottish Enlightenment. Mary Catherine Moran taught in the Department of History at Columbia University.