 Leibniz might be the first Russellian monist. In his view, all the properties physics presents are either extrinsic or relatively intrinsic. This corresponds to structuralism about physics. He contends there are absolutely intrinsic properties, primitive forces on one reading, in which those extrinsic properties and relatively intrinsic properties are grounded. This corresponds to realism about quiddities. Those quiddities ground all of the other features of reality, including consciousness generally and macrophenomenal properties specifically. This corresponds to quidditism about consciousness. Thus, Leibniz seems to endorse versions of all three core Russellian monist theses. And because on his view all basic entities, including Leibnizian quiddities and the extrinsic and relatively intrinsic properties they ground, are mental, Leibnizian Russellian monism is a version of Russellian idealism.