, born , was a Japanese

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 nationalist thinker of the Mito school

Mitogaku

Mitogaku refers to a school of Japanese historical and Shinto studies that arose in the Mito domain, in modern-day Ibaraki prefecture.The school had its genesis in 1657 when Tokugawa Mitsukuni , second head of the Mito domain, commissioned the compilation of the Dai Nihon-shi...

 during the late shogunate period.

In 1799 he became involved in the compilation of the Dai Nihon-shi (Great History of Japan) being undertaken by the Mito school.

In 1825 he wrote his Shinron ("New Theses"), a collection of essays that mainly dealt with the concept of kokutai

Kokutai

Kokutai is a politically loaded word in the Japanese language, translatable as "sovereign", "national identity; national essence; national character" or "national polity; body politic; national entity; basis for the Emperor's sovereignty; Japanese constitution". "Sovereign" is perhaps the most...

("national polity"), a term which Aizawa popularised. The Shinron warned of the threat of foreign ships and later became an important work for the sonnō jōi

Sonno joi

is a Japanese political philosophy and a social movement derived from Neo-Confucianism; it became a political slogan in the 1850s and 1860s in the movement to overthrow the Tokugawa bakufu, during the Bakumatsu period.-Origin:...

 movement.

In 1840 Aizawa became the first head of professors of the Mito school's Kōdōkan but was forced to resign in 1844 when Tokugawa Nariaki

Tokugawa Nariaki

Tokugawa Nariaki was a prominent Japanese daimyo who ruled the Mito domain and contributed to the rise of nationalism and the Meiji restoration.- Clan leader :...

resigned as domain leader. He later returned to the Kōdōkan.

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