 It is not as obvious why the concept of nature, or the natural, looms large in Cicero’s account of law. One of its main purposes is, again, to stress that he is conducting a normative enquiry. We are, he says, ‘born for justice’, and what is right is a matter not of opinion but of nature (1.28). Here Cicero draws upon a tradition, already going back at least as far as Plato, in which nature stands in contrast with convention. What is merely a matter of convention or opinion is not the same as what is really – ‘by nature’ – the case. Thus the fact that a certain (human-made) law states that something is right or wrong does not mean that its pronouncements are correct.