Porphyry and Plotinus on the Seed

Porphyry's account of the nature of seeds can shed light on some less appreciated details of Neoplatonic psychology, in particular on the interaction between individual souls. The process of producing the seed and the conception of the seed offer a physical instantiation of procession and reversion, activities that are central to Neoplatonic metaphysics. In an act analogous to procession, the seed is produced by the fathers nature, and as such it is ontologically inferior to the fathers nature. Thus, the seed does not strictly speaking contain a full-fledged vegetative soul. Rather, it acquires its vegetative soul only while it is being actualized by an actual vegetative soul. This actualization takes place primarily at conception, where the seed as it were reverts back and becomes obedient to the mothers nature, but continues through the period of gestation. In this way, Porphyry can account both for maternal resemblance and for ideoplasty. He uses the Stoic language of complete blending to describe the mothers relation to the seed and embryo, and this reveals that he thinks of individuals as having their own unique individual natures (as opposed to sharing in a single universal nature). In the course of developing this theory, Porphyry makes significant revisions to his philosophical predecessors' views in both embryology and botany. He revises Aristotle's verdict on the relative importance of the female in generation as well as Theophrastus' explanation of the biological mechanics of grafting. Although Plotinus nowhere addresses embryology in the same detail as Porphyry does, we can conclude from his remarks on seeds and plants that his own views were similar to those of his student.