Historians of science have long considered the very idea of a law-governed universe to be the relic of a bygone intellectual culture that took it largely for granted that a divine lawmaker existed. Many philosophers of science today insist that the claim that laws of nature are hardwired into the fabric of physical reality is laden with implausibly theological assumptions, preferring instead to treat them as theoretical axioms in an optimal description of nature's regularities, or else as robust patterns of causal connections or causal powers whose status can be reconciled to the stringent demands of metaphysical naturalism. Yet the metaphor of lawhood has proven more difficult to dislodge than the theistic commitments it once presupposed, not least because it preserves the widespread intuition that the task of scientific inquiry is not to stipulate the difference between a lawful and an accidental regularity in nature, but to discover it. Taking its cue from the repeated failure to find naturalistic alternatives to divine lawmaking, this book undertakes a retrieval and reappraisal of a high-scholastic philosophy of nature that grounds lawlike regularities in the conceptual and causal powers of God and, having done so, concludes that the metaphysical framework of classical theism yields a more powerful and parsimonious explanation of the rhythms and patterns of the natural world than its secular rivals.