The term "divine" in soul, and "spirit" in spiritual soul, each have their own explanations.
Spirit generally refers to intelligence and spirituality. Humans are born with intelligence and spirituality, thus their soul
can be called a spiritual soul.
However, beasts and plants, though possessing spirituality, find it difficult to awaken intelligence, hence their souls remain incomplete.
Only those demon beasts that have awakened intelligence can complete their souls, forming a beast soul.
The term divine, thus, refers to the divinity within the human body.
Once a cultivator's soul moves into the Purple Mansion, it transforms into a divine soul, thereby gaining all sorts of mystical abilities.
The divine soul is also the divinity of the human body, overseeing all bodily organs and systems, including mana and other elements.
A simple example is the human neural response system, which isn't directly controllable by the human will. But the divine soul can control it.
