Natural Law Theory

Abstract

In this chapter we will critically examine natural law theory and the proposal that there is a necessary connection between positive (human-created) family law and natural family law (objectively valid, universal moral rules not created by humans). Natural law theory, as it applies to family law, proposes that the rules of positive family law are valid only if they conform to the rules of natural family law. Our question is whether this theory can be successfully defended. We begin with a description of a Supreme Court case invalidating a state statute prohibiting sexual activity and marriages between persons of different races, in which the prohibition was partly based on appeals to natural law. We will then test several versions of natural law theory, beginning with a classical version originally proposed in the seventeenth century by the English philosopher John Locke. We conclude with a discussion of two modern versions of the theory proposed and defended in the twentieth century by American philosophers Lon Fuller and Ronald Dworkin.