Unus Mundus

Unus mundus, Latin for "One world," is the concept of an underlying unified reality that everything emerges from and returns to.

The idea was popularized in the 20th century by Swiss psychoanalyst Carl Jung, though the term can be traced back to scholastics such as Duns Scotus and was taken up again in the 16thC by Gerhard Dorn, a student of the famous alchemist Paracelsus.