 A fourth recent objection to Russellian monism targets the distinction between the structural and the non-structural. Some argue that this distinction cannot be explicated in the way that Russellian monism requires. As noted above  (section 1.1),  some have made proposals for how to explicate that distinction. Those proposals render structuralism about physics consistent with the claim physics describes some intrinsic properties, thus safeguarding structuralism about physics from one line of attack. But whether any of those proposals is fully adequate for the purposes of Russellian monism is disputed (Stoljar 2015). Other, related objections have been raised, e.g., that the dispositional/categorical distinction does not apply to physical properties in the way that Russellian monism implies (Hiddleston 2019; for other objections concerning the Russellian monist’s structural/non-structural distinction, see Stoljar 2006, 2009, 2014, 2015; Ney 2015; for responses, see Pereboom 2011, 2014, 2015; Alter 2009, 2016).