In this paper I revisit nature as a source of normativity for law in the later Hellenistic period, that is beyond the opposition of law and nature in the early classical period, Plato’s and Aristotle’s naturalism, or the early Stoics’ conception of the common law. I will focus on the first century BCE, when the expression ‘natural law’ gained prominence, reconstructing its origins in the interaction between Hellenistic philosophers and the Roman elite, including jurists. I argue that for the jurists the Stoic doctrine of law in nature offered a theoretical underpinning for their unique practice of dispute resolution, whereas for the Stoics this Roman practice offered an unexpected opportunity to instrumentalise their conception of law.