>>508068945 (OP)Konnichiwa, OP-kun.
Read about the fundamentals of classical scholarship.
https://www.britannica.com/topic/classical-scholarship
>how do we know ancient scriptures aren't some schizo fanfic?I will be very honest with you. In antiquity, history was primarily meant to be entertainment first, facts second. Thucydides was a major exception to this. So yes, a decent amount of ancient history is indeed schizo fan fiction. Hence the importance of strict scholarly standards, archeology, and cross-disciplinary scholarship.
t. classicist