Sokichi TSUDA argued in his "Nihon Jodaishi Kenkyu" (Research in the ancient history of Japan) published in 1930 that Jushichijo Kenpo was not made by Shotoku Taishi (his four books including "Nihon Jodaishi Kenkyu" became prohibited books and Sokichi TSUDA resigned his post at Waseda University).
また、津田左右吉は1930年の『日本上代史研究』において太子作ではないとしている（『日本上代史研究』ほか著書四冊は発禁となり、津田左右吉は早稲田大学を辞職した）。