With the growth of militarism after the Great Depression of the 1930s, although Tatsukichi MINOBE's theory that the Emperor was an organ of the state was the main theme at academic conferences, it was regarded as questionable and books on this subject were banned in 1935, and then in 1940, criticism of the mythology of the Kojiki and the Nihonshoki by Sokichi TSUDA, a professor of Waseda University, became an issue so the publication of books on this subject was also banned.
世界恐慌を経て軍国主義が台頭するに及び、昭和10年（1935年）、美濃部達吉の天皇機関説が学会では主流であったにも拘らず問題視されて発禁処分となり、昭和15年（1940年）には早稲田大学教授津田左右吉の記紀神話への批判が問題となり著作が発禁処分となった。