Kokugaku was a study that took place in the mid-Edo period in Japan. It was one of the studies that represented the Edo period along with Ran Gaku (Dutch learning). It was also called Wagaku, Kochogaku, Kogaku, and Kodogaku.
Kokugaku criticized the heretofore strong academic focus on Confucian and Buddhist classics, especially the "Four Books and Five Classics" of Confucianism, trying instead to unearth native Japanese cultural, philosophical, and spiritual traditions to be found in the Japanese classics and ancient histories.
Yet the methodology of Kokugaku was heavily influenced by Jinzai ITO's Kogigaku (a Confucian school) and by Sorai OGYU's Kobunjigaku (study of ancient rhetoric) even though Kokugaku scholars criticized these schools. Kokugaku rejected the moral philosophy of both Confucianism and Buddhism, which forced people to repress natural human emotions, instead placing value on the natural expression of human emotions.
It appeared as a form to criticize medieval Kagaku (Study of Japanese poems called waka) that lost it's popularity during the Edo period. The criticisms that started with Katsutoshi KINOSHITA and Mosui TODA continued in the research of "Manyoshu" (The Collection of Ten Thousand Leaves) conducted by Choryu (also pronounced "Nagaru") and Keichu SHIMOKOBE. In particular, the tendency towards positivism seen in Keichu's work was greatly praised for raising the academic standards of research into the Classics. In addition, Azumamaro KADANO, a Shinto priest of Fushimi Inari Shrine, contributed his "Kodoron" (Theory on the Ancient Ways), in which he tried to recapture the essence of ancient Japan by studying Shinto and the Japanese Classics. KAMO no Mabuchi formalized Kokugaku as academia by even incorporating some contradictions made by Keichu and Kokugaku of Azumamaro KADANO. Mabuchi rejected Confucian thought and believed that the true spirit of the ancient Japanese was to be found in the "Manyoshu", devoting his life to researching it.
Norinaga MOTOORI, one of Mabuchi's disciples, researched the "Kojiki" (Record of Ancient Matters), stressing that the ancient Japanese had been closely connected to the gods, and also completed the "Kojikiden" (Commentary on the Kojiki), in which he advanced the literary theory of "mono no aware" (the pathos of things).
Atsutane HIRATA, a disciple of Norinaga's, later developed the ideas expressed in Norinaga's "Kodoron" into the "Fukko shinto" (Restored Shinto), a new form of Shinto. Atsutane's ideas influenced both the development of the Sonno joi (revere the Emperor, expel the barbarians) ideology at the end of the Edo period as well as the principle of Kokujun (keeping Japan's culture pure) and Kokokukan (the theory that Japanese history is centered around Japan's Emperors), both of which stressed the preeminence of Japan. Atsutane's ideas also frequently found expression in works such as "Suito hiroku" and "Kondo hisaku" by his disciple, the intellectual Nobuhiro SATO.
However, some--including Harumi MURATA, a disciple of Mabuchi--belonged to schools of thought that criticized Atsutane's Kokugaku from the standpoint of, since the time of Keichu, espousing positivism and placing great value on the study of classic works, arguing that internally it was more complex than that. Kokugaku, which stressed positivism became the basis of modern Japanese Literature, National Language, and Ethnology studies because of the work of Kiyonori KONAKAMURA.