Scholars of religion have debated how to classify Shinto. Inoue considered it part of "the family of East-Asian religions". The philosopher Stuart D. B. Picken suggested that Shinto be classed as a world religion, while the historian H. Byron Earhart called it a "major religion". In the early 21st century it became increasingly common for practitioners to call Shinto a nature religion. It is also often described as an indigenous religion, although this generates debates over the various different definitions of "indigenous" in the Japanese context. The notion of Shinto as Japan's "indigenous religion" stemmed from the growth of modern nationalism in the Edo period to the Meiji era; this view promoted the idea that Shinto's origins were prehistoric and that it represented something like the "underlying will of Japanese culture". The prominent Shinto theologian Sokyo Ono, for instance, said kami worship was "an expression" of the Japanese "native racial faith which arose in the mystic days of remote antiquity" and that it was "as indigenous as the people that brought the Japanese nation into existence". Many scholars regard this classification as inaccurate. Earhart noted that Shinto, in having absorbed much Chinese and Buddhist influence, was "too complex to be labelled simply" as an "indigenous religion".