Daigen 大玄 (Tenna 2 / 1682 – Hōreki 8 / 1758), mid-Edo Jōdoshū scholar-monk and educational reformer associated with Zōjō-ji 増上寺 (the Tokugawa-clan tutelary Jōdoshū head temple in Edo) and its affiliated Kantō academies (the Kantō jūhachi danrin 關東十八檀林 — eighteen Jōdoshū teaching academies of the Kantō region). His work KR6t0325 Renmon gakusoku 蓮門學則 (“Curriculum of the Lotus Gate”) sets out the educational protocols for young monks entering the Jōdoshū system, with the curriculum divided into eight successive three-year courses (the Hachi-bu 八部 eight-part scheme): Myōmoku-bu 名目部, Ju-gi-bu 頌義部, Senchaku-bu 選擇部, Shō-gengi-bu 小玄義部, Dai-gengi-bu 大玄義部, Monku-bu 文句部, Raisan-bu 禮讃部, Ron-bu 論部, plus Mu-bu 無部. Daigen’s text is the principal documentary witness to the Edo-period institutional pedagogy of Jōdoshū and was reprinted in Bunsei 10 / 1827 with a preface noting that the Daisōjō Jōyokō 大僧正成譽公 (a senior Jōdoshū prelate) had used it as a teaching primer for novices.
Little is known about Daigen beyond his ecclesiastical-pedagogical writings; he is one of many mid-Edo danrin (academy) scholars whose principal contribution was to the gakumon-bukkyō (scholastic Buddhism) of the Tokugawa institution rather than to original doctrinal thought.