The theory of the Dark and the Light and the idea of unworldly men's world, which Atsutane taught based on Kodo, were, in fact, Chinese ancient philosophies that had been introduced in centuries past, especially Gengaku ('xuanxue', philosophy fused by Confucianism and Taoism during the period from the third century until the fifth century) and Shinsendo ('shenxiandao', method for becoming unworldly man); Gengaku was regarded as the scholar to analyze the essence beneath the surface of the phenomenon.
篤胤の提唱する古道に於ける幽顕の弁や神仙思想とは、実は皇国に古来から伝播した玄学(神仙道)の事であり、玄学とは現象を動かす物の奥にある本質を解明する学問の事である。