Radical criticism is a movement around the late 19th century that, typically, denied authentic authorship of the Pauline epistles. This went beyond the higher criticism of the Tübingen school which (with the exception of Bruno Bauer) held that a core of at least four epistles had been written by Paul of Tarsus in the 1st century.
The Dutch school of radical criticism started in 1878 with a publication by Allard Pierson, who denied Pauline authorship of Galatians. He was fiercely attacked by his colleague A. D. Loman, but two years later also Loman abandoned the historicity of Paul. Similarly, W.C. van Manen, who had written a doctoral thesis defending the authenticity of 1 Thessalonians, wrote in 1889 that he had come to the same conclusions as Loman. Also the philosopher G. J. P. J. Bolland was a part of this movement. With the death of Van Manen's student G. A. van den Bergh van Eysinga in 1957, this line of scholarship at Dutch universities came to an end.
The name "Dutch Radicals" was coined by A. D. Loman, in an 1887 article reviewing Edwin Johnson ("Antiqua Mater: A Study of Christian Origins", 1887), saying that "the author is a radical like we seldom meet among theologians and hardly ever among English theologians". The RadikalKritik article on van Manen and the Dutch Radicals adds that "Van Manen later spoke of the ‘radical’ or the ‘Dutch’ school (1902). The ‘radical’ scholars did not want to be impeded by church canons and wanted to be free in their research of the New Testament and of the history of early Christianity. This research led them to the conclusion that we do not have any authentic Pauline epistles."