Ignorance

A monstrous birth prepared its cosmic form
In Nature’s titan embryo, Ignorance.
     — Book 2 Canto 8

Ignorance is represented by Typhon (See It was the hour before the Gods awake). It is incompatible with the overmind. This is why the fight against Typhon was the first great battle of Zeus, who stands for the highest power of the overmind, after his victory over the Titans. The latter marked the end of humanity’s vital childhood and its entry into the discerning mind.