Peirce's discussion of the meaning of symbols helps clarify what is at stake in his debate with the nominalist. As he sees it, the central issue is whether the continuity presupposed by the laws affirmed in symbols is real. While this is a question of ontology, he thinks it is settled by appeal to experience, like any other scientific question. However, on his theory of symbols it is unclear how experience might lead an inquirer to credible beliefs about which – or indeed whether any – laws obtain. According to the pragmatic maxim, a proposition like ‘The Kohinoor diamond is hard’ means that ‘If a scratch test were performed on the Kohinoor diamond, it would remain unmarked in every case.’ Peirce thinks an inquirer can reasonably judge this to be the case only given evidence supplied by scratch tests (carried out on this or other diamonds). However, any judgement about the results of any such test – for example, ‘The Kohinoor diamond passed a scratch test on 15 January 2010’ – also implies a law, a law to the effect that if certain actions indicating that the Kohinoor diamond passed a scratch test on this date were performed, certain practical effects would result. To affirm this law an inquirer would seem to require evidence provided by experimental tests that pertain to it.