Classical natural law theory derives moral conclusions from the essentialist and teleological understanding of nature enshrined in classical metaphysics. The paper argues that this understanding of nature is as defensible today as it was in the days of Plato, Aristotle, Augustine, and Aquinas. It then shows how a natural law theory of the grounds and content of our moral obligations follows from this understanding of nature, and how a doctrine of natural rights follows in turn from the theory of natural law. With this background in place, the implications of the theory for questions about property rights and taxation are explored. It is argued that classical natural law theory entails the existence of a natural right of private property, and that this right is neither so strong as to support laissez faire libertarianism, nor so weak as to allow for socialism. Though the theory leaves much of the middle ground between these extremes open to empirical rather than moral evaluation, it is argued that there is a strong natural law presumption against social democratic policies and in favor of free enterprise.