 Some defenders of the regularity theory see the dependence on epistemic components as a problem. To solve it, one may want to posit that there are natural properties which carve nature at its joints. The idea is that those natural properties provide a fully objective classification. Those natural properties would ensure that the lawlike regularities are free of epistemic components. However, what is natural is notoriously difficult to define. Natural properties, which are objectively similar and dissimilar to each other, are thus often simply posited as primitives which are not analysed further, as Lewis (1986: 60–2) does for example.