Even for Leibniz, whose later monadological metaphysics was perhaps closer to Berkeley’s immaterialist philosophy, an opposition to materialism didn’t necessarily imply immaterialism. Leibniz had resisted Descartes’ postulation of distinct spiritual and material substances, treating corporeal bodies as inseparable combinations of form and matter after the manner of Aristotle. The materialists to which he was opposed (mechanistic corpuscularists of his time) conceived of unformed matter as a type of self-subsistent substance, and it seems to have been that conception to which he was opposed, at least in some periods of his work, not the reality of matter per se. Leibniz’s combination of Platonic and Aristotelian notions played a role in the thought of the later idealists, giving their opposition to materialism its distinctive character. These anti-immaterialist features of the idealism of the Germans became more prominent in the post-Kantian period as they moved progressively away from the more subjectivistic features of Leibniz’s thought (Beiser 2002).