I’m poring over some stuff I’d written about individuation and found a little part to share here. The image is physiological, but keep in mind its psychological relevance:
Individuation is to be distinct from the world around you. Not isolated, but distinct. It is in this way you can function in the world. Most organisms have to be, in some way, physiologically individuated in order to function well in the world. The cells that comprise my body have to be individuated from one another if my body is not to reduce into a useless blancmange.