Soujirou Sanada is a Japanese philosopher, film director, and musician from Hyogo Prefecture. A scholar of Oswald Spengler, he teaches philosophy while working across fields including theories of civilization, intellectual history, the ontology of death, ethics, and artificial intelligence. He also wrote, directed, and starred in the feature film "Okamoto Manta," which won the CineRebels Award at Filmfest München. In "Yoninsho no Tetsugaku: AI to Tou, Bunmei oyobi Jinrui," Sanada uses philosophical dialogues with AI to examine an entity that produces responses without human-like subjectivity or responsibility. Introducing the concept of a "fourth person" as a way of understanding AI beyond the conventional first, second, and third persons, the book uses the differences between humans and AI to reconsider language, consciousness, ethics, art, and civilization.