Saturn and the ego

In Handbook for a Humanistic Astrologer , michael Meyer says that Saturn is the ego.

I thought the moon/cancer/4th was the ego?

Could I ask for a clarification on this from EA perspective?

I’ll quote what he says specifically:

“ the dyad of identification and adaptation is the symbolic molding force behind the establishment (moon ) of the ego (Saturn) and its gradual development (moon) into a distinct individual (Saturn)”.