By the eighteenth century the Kojiki was effectively unreadable. It was written in Chinese characters used inconsistently — sometimes for meaning, sometimes purely for the sound of eighth-century Japanese — and no reliable reading tradition survived; scholars used the Nihon Shoki, written in proper classical Chinese, instead. Motoori Norinaga, a physician in Matsusaka, spent thirty-four years, from 1764 to 1798, producing the Kojiki-den, a forty-four-volume commentary that reconstructed the phonology and made the text legible again. It is by common agreement one of the great works of philology anywhere. Norinaga's second contribution was interpretive and more consequential: he argued that beneath the Chinese overlay of Buddhist and Confucian thought lay a native Japanese sensibility — direct, feeling, sincere, expressed in mono no aware — which had been corrupted by imported systematising. That argument founded kokugaku, national learning, and its nineteenth-century successors turned it into an ideology of Japanese uniqueness and imperial restoration. Norinaga died in 1801 and did not choose what was done with it.