Aizawa Seishisai

In 1825 he wrote his Shinron ("New Theses"), a collection of essays that dealt with issues such as Tokugawa defence policy and how the ships were a threat to Japan.

Aizawa also tried to describe conditions in the West and theorize why those states had gained so much control; in his opinion Westerners used religion to inculcate conformity in the masses.

He also claimed that Christianity was used by the colonial powers to subvert native cultures and governments by creating a fifth column that would collaborate with and facilitate military conquest by Europeans.

Furthermore, he believed that if Japan's way of life was to survive, it would need to take up its own state religion in order to prevent cultural assimilation via Christianization and discussed the concept of kokutai ("national polity") in this context.

The Shinron would become an important work for the sonnō jōi movement and his theory of the Kokutai would be developed by future thinkers.