It was Encho TAMURA who inverted the trends in which the Imperial Succession theory was going to be an accepted theory, and in his article 'A study of Fukai-no-Joten/ Fukaijoten' presented in 1969, he criticized the Imperial Succession theory across the board, and presented the theory that it was to establish the assisted government system by the Fujiwara clan.
皇位継承法説定説化の状況を覆したのは田村円澄で、1969年に論文「不改常典考」で皇位継承法説を全面的に批判し、藤原氏による輔政体制とする説を発表した。