Natural law links moral and legal theory with natural theology and science. It is critical to thinking about God’s sovereignty and human freedom. Tracing the roots of the natural law idea, I defend the approach against conventionalism and legal positivism. For they leave human norms ungrounded. Chapter 7 opens by disarming Hume’s elenchus about ‘is’ and ‘ought’. I do not deny the reality of a naturalistic fallacy, but I do argue that facts make rightful claims on us and that the unity of reality and value central to Jewish thinking and to the philosophical great tradition does not confuse facts with values but does appreciate the preciousness of being—of life and personhood most pointedly. Once again here transcendence consorts with immanence. For we find God’s law writ subtly in nature, not least when we discover what it means to perfect ourselves as loving and creative human beings.