It is generally understood that he was extremely dedicated to learning, and enthusiastically studied history under the tutelage of Hakuseki ARAI on matters including achievements gained by Ieyasu TOKUGAWA, the first shogun, Hidetada TOKUGAWA, the second shogun and his great-grandfather, and Iemitsu TOKUGAWA, the third shogun.
無類の学問好きで、新井白石から初代将軍・徳川家康、曽祖父の2代将軍・徳川秀忠、祖父の3代将軍・徳川家光の事跡など、歴史について熱心に学んだといわれる。