In brief, while advocating Kodo, Atsutane had been studying Japanese original Shinsendo that was a fusion of Japanese ancient philosophy about gods and Chinese Taoism.
篤胤にとって古道学とは日本古来の神代思想と支那の老荘道家の思想を融合した皇国伝来の独自な神仙道の思想である事に気づく。