 A first strategy, which we can call the locationist strategy, is to define parthood in terms of the location relation together with the subregion relation (Oppenheim and Putnam 1958; Markosian 2014). For example, one might say that for x to be a part of y is for x's exact location to be a subregion of y's exact location. To avoid circularity, friends of the locationist strategy should reject Subregions as Parts, in favor of either (i) the view that regions are sets of points and x is a subregion of y if and only if both are regions and x is a subset of y or (ii) the view that subregionhood is primitive and fundamental. An objection to (i) is that regions are concrete, whereas sets are abstract, not concrete; an objection to (ii) is that positing a fundamental relation of subregionhood seems very similar to, and probably no more theoretically virtuous than, positing a fundamental parthood relation (though see Nolan 2014: 105–111). There are two main objections to the locationist strategy more generally.