Before the story begins, the author wants to popularize a little knowledge. If you don't like it, you can go directly to the story and read it.
What is metaphysics? Metaphysics, the word "Xuan" here, originates from a sentence in "Laozi", "Mysterious is mysterious, and it is the door to all mysteries." Metaphysics is originally a term in Taoist (Taoist) philosophy, referring to a philosophical trend that emerged in the Wei and Jin Dynasties with "Laozi" as its core study. In modern times, it generally refers to all theories that study the unknowable ontology. In the debate between science and metaphysics, its connotation has been expanded to the extreme. Everything that is unknowable and incredible, and that science cannot explain and cannot relate to, seems to be included in the category of metaphysics.
Some people say that metaphysics is the science of the unknown, and science is the metaphysics of the known.
Concept: Metaphysics is the science of the unknown, and science is the metaphysics of the known.