Most legal thinkers believe that legal rules and legal principles are meaningfully distinguished. Many jurists may have no very precise distinction in mind, and those who do might not all agree. But it is widely believed that legal norms come in different logical types, and that one difference is reasonably well captured by a nomenclature that distinguishes “rules” from “principles.” Larry Alexander is the foremost challenger to this bit of legal-theoretic orthodoxy. In several articles, but especially in “Against Legal Principles,” an influential article coauthored with Ken Kress two decades ago, Alexander has argued that legal principles cannot exist. In this essay, I argue that Alexander and Kress have not established their ambitious claim. Even if they have shown that legal principles, understood as norms distinct both from legal rules and from moral principles, cannot perform the function that Ronald Dworkin assigned them – namely, that of morally justifying legal rules and practices – Alexander and Kress have cast no doubt on a distinctively positivist account of legal principles as fundamental legal norms that possess weight, are grounded directly in social facts, and serve to metaphysically determine or constitute legal rules. I show why that positivist picture of legal principles survives Alexander’s multipronged attack. And I further explain why the existence of legal principles causes grave trouble for Alexander’s “simple-minded” defense of constitutional originalism.