After World War II, the Japanese geological community was involved in a passionate movement for democracy. In 1947 an association so called "Chidanken" was founded for the purpose of democratizing the geological community and collaborating on the geological research. Chidanken also generated a new research tradition that could be named "Historicism". The research tradition, which, became dominant in the Japanese geological community in 1950s, placed a special emphasis on discovering the law of the earth evolution. The historicism research tradition also produced geosynclinal mountain-building theory that had the idea that geosynclines possessed mountain-building forces within them. While there was another research tradition which remained since European geology had been introduced in the mid-nineteenth century. That could be named "Actuarism". There were many controversies over an origin of volcanic rocks and so on between the above two research traditions from 1950s to the beginning of 1970s. When plate tectonics was introduced into Japan in the end of 1960s, the adherence of the historicism research tradition did not accept plate tectonics, because plate tectonics was built on "Actuarism". Moreover geosynclinal mountain-building theory conflicted with plate tectonics that accounted for mountain-building as a consequence of plate motion. Consequently, it was not until the middle of 1980s that plate tectonics was generally accepted in the Japanese geological community.