Many concepts and ceremonies from Koshinto were introduced into Japanese society during the late Edo period, their popularization tied to the rise of both the sonno joi (revere the Emperor, expel the barbarians) philosophy and the Hirata school of Kokugaku, but few historical records detailing Koshinto influence survive today, so much like the case of primitive Buddhism, it seems it is in fact only possible to make inferences on Koshinto based on later documents or by analogy.
江戸時代末期に、古神道と称する思想や儀礼などが、尊皇攘夷思想や平田国学の隆盛と連動して、世に出たものが多くあるが、しかし当時の記録文書は無きに等しく、原始仏教同様、実際には後世の資料などから、間接的に推理・類推される存在に過ぎないことも指摘されている。