Lower Domain

From Xenosaga Wiki

The Lower Domain is a single unit, while possessing two domains: the imaginary number domain and the real number domain. That complex structure itself is the underlying reason why the profoundness in our lives is born, why we feel mystery in the world, and why we believe in infinite possibilities.

The lower domain is organized according to the imaginary and real number domains. The imaginary number domain can be described as the domain of consciousness, or the domain of concepts, or perhaps even the domain of the soul. And the real number domain is considered to be the domain of substance. These two domains exist as two sides of the same coin, and all things that exist in the real domain, the material domain, also exist in the imaginary domain, the spiritual domain. This would have been considered similar to the world of the soul spoken about by religions that existed in many numbers in the era of Lost Jerusalem.