 Lastly, properties play a prominent role in two well-known accounts of the  laws of nature:  the nomological necessitation account and law dispositionalism. The former has been expounded by Tooley (1977; 1987), Dretske (1977) and Armstrong (1983). Roughly, following Armstrong, a law of nature consists in a second-order and external nomological necessitation relation \(\rN\), contingently holding between first-order universals \(P\) and \(Q\): \(\rN(P, Q)\). Such a higher-order fact necessitates certain lower-order regularities, i.e., all the objects that have \(P\) also have \(Q\) (by nomological necessity, in virtue of \(\rN(P, Q))\). Law dispositionalism interprets laws of nature by appealing to dispositional properties. According to it, laws of nature “flow” from the essence of such properties. This implies that laws of nature hold with metaphysical necessity: whenever the dispositions are in place, the relevant laws must be in place too (Cartwright 1983; Ellis 2001; Bird 2007; Chakravartty 2007; Fischer 2018; see also Schrenk 2017 and Dumsday 2019). (For criticisms, see, e.g., van Fraassen 1989 as regards the former approach, and McKitrick 2018 and Paolini Paoletti 2020b, as regards the latter).