 If one rejects not just the details but the general program of analysing lawhood in terms of naturalness, one might instead consider an analysis of naturalness in terms of lawhood: “natural properties are the ones that figure in laws of nature” (Lewis  1983,  344). (If one is analysing perfect naturalness, one might want to specify that the laws should be “basic” rather than “derived”.) A central challenge for working out this program is to explain what ‘figure in’ means. To get anything like the desired extension for ‘natural’, we need an extremely fine-grained theory of propositions. For example, unless we are comfortable with the consequence that being either non-\(F\) or \(G\) is perfectly natural whenever the proposition that everything \(F\) is \(G\) is a law, we will need to deny that that property “figures in” that proposition. This will plausibly require denying that the property is identical to the proposition that everything is either non-\(F\) or \(G\), and denying that the latter proposition is a law despite its necessary equivalence to the former. As we will see in  §4.10  below, there are formidable obstacles to developing a consistent theory of properties and propositions that is fine-grained in the needed  ways.[46]  The thesis that only perfectly natural properties “figure in” (basic) laws of nature also faces other objections. For example, Hicks and Schaffer  (2017)  argue against it on the grounds that, for example, acceleration figures in a basic law, namely \(F=ma\), but is not perfectly  natural.[47] 