Back in my original world, many people had repeatedly studied dreams before. However, nobody had been able to find anything conclusive.
Why did people dream? Why did people see certain dreams? Were dreams connected to reality?
Even now, science was still unable to give an explanation for dreams. Only religion and philosophy had explanations for them. Some people even started practicing divination by interpreting dreams.
Oftentimes, dreams were viewed as precautions or warnings. Modern science was still unable to explain dreams, as there were many things still unknown about the brain.
But in the magical world of Eich, things were different. Eich wasn't a world of science to begin with.
While people were asleep, the soul would still drowsily move around. Pure consciousness would create an illusionary realm that mages referred to as the source of dreams.