This paper attempts to determine what laws’ most fundamental normative property is for Plato. After examining the Hippias Major and the pseudo-Platonic Minos, I argue that in the Laws this property is correctness (orthotês) which is understood as maximizing the citizens’ happiness. I argue that laws failing to do so are defective as laws because they’re not partially grounded in the relevant ethical facts and that Plato is thus a natural law theorist. The last section provides further justification for the (...) claim that laws failing the correctness criterion are defective as laws by appealing to Plato’s understanding of practical rationality. (shrink)