The Individuation Problem for Plant Souls in Panpsychist Ontology

In this paper, I develop a metaphysical problem for panpsychism, which I call the individuation problem, by treating plants as a test case. Gustav Fechner, a 19th-century panpsychist, views plants as possessing souls (die Seele) or a conscious mental state. However, I argue that his visionary metaphysics falls short in articulating the conditions under which a plant soul is individuated. This problem persists in contemporary analytic panpsychism, which focuses primarily on the combination problem but often presupposes that macro-subjects are well-defined and centralised. Plants, by contrast, exhibit de-centralised, modular, and physiologically fused architectures. Given their structural and ontological indeterminacy, this raises the question of how plant souls or plant-level conscious subjects are individuated within a panpsychist ontology. This renders them metaphysically ambiguous in ways that panpsychism has not accounted for. This paper is structured to present dilemmas and problematise the panpsychist systems and assumptions. I conclude that any serious panpsychist theory must either address these challenges or abandon its claim to universality.