 There are, however, two other issues about the relationship between grounding and necessity that are less of a settled matter. The first is whether it’s necessary that (full) grounds necessitate what they ground—according to necessitarianism, necessitation is necessary for grounding. The second is whether grounding is an internal relation in the following sense: it’s necessary that if \([P],\) \([P'],\) … (fully) grounds \([Q]\), then any metaphysically possible world in which \([P],\) \([P'],\) … and \([Q]\) obtain is a world in which the former (fully) grounds the latter. According to internalism, grounding is internal in this sense. Internalism entails necessarianism but not vice versa. Due to limitations of space, we focus on necessitarianism in what follows. (See Bennett 2011, Litland 2015, Carnino 2017, and Lovett 2019 for discussion of internalism.)