Unpopular in its day, David Hume's sprawling, three-volume A Treatise of Human Nature (1739-40) has withstood the test of time and had enormous impact on subsequent philosophical thought. Hume's comprehensive effort to form an observationally grounded study of human nature employs John Locke's empiric principles to construct a theory of knowledge from which to evaluate metaphysical ideas. A key to modern studies of eighteenth-century Western philosophy, the Treatise considers numerous classic philosophical issues, including causation, existence, freedom and necessity, and morality.
