What matter matters as a matter of justice?

With planet-wide environmental unravelling ideas of multispecies and planetary justice are gaining multidisciplinary attention. They frame a set of ethical, moral and political obligations to life-on-Earth. While it is clear it is humans who bear the duties and obligations of justice, who or what is the subject of justice-beyond-human varies widely: Some limit the subject to sentient animals, others include all living things. We argue for a more expansive subject that includes both living and non-living matter. We claim that privileging living/life is an anthropocentric categorisation embedded in the foundational epistemologies and ontologies driving environmental damages, resource conflicts and mass extinction. An exclusion of matter from concerns of justice ignores multiple fundamental more-than-human relationships in humans' every-day material lives. We argue that the subject of planetary justice must be expansive - addressing sentient or not, living or not, animal, vegetable, mineral, and elemental - to be inclusive, applied, plural, and sustainable.