This book was among the first to argue that the Imperial forces were defeated in the war because the retired Emperor Gotoba was an "evil king" who lacked virtue, so the defeat didn't mean repudiation of emperors or Japan as the land of the gods.
その中で、同書はいち早く、乱の敗北の原因を後鳥羽上皇が不徳の「悪王」だったからであり、天皇および神国・日本が否定されたわけではないという論調で書かれている。