Sorai radicalized Itō Jinsai's philological method into Kobunjigaku ("Ancient Rhetoric" learning), arguing that the Confucian classics - especially the Six Classics attributed to the ancient sage-kings, not only the Analects and Mencius - must be read strictly in their original ancient Chinese linguistic and historical context rather than through Song-dynasty Neo-Confucian metaphysical interpretation. He argued the Confucian "Way" names specific institutions, rites, and music instituted by the sage-kings for governing society, not an innate moral principle discoverable through introspection.
Intellectual setting
Sorai wrote as an influential advisor to the Tokugawa shogunate during a period of consolidating bureaucratic rule, and his historicist, institutional reading of Confucianism directly informed his practical political consulting on matters of governance and social order.
Key ideas
Kobunjigaku (ancient philology)
Sorai argued that later commentators, especially Song Neo-Confucians, had projected anachronistic metaphysical meanings onto the classics, and that recovering their authentic sense requires philological attention to the original ancient Chinese language and historical context in which the sage-kings wrote.
The Way as sage-kings' institutions, not innate principle
Sorai held that the Confucian Way refers to the concrete rites, music, and political institutions instituted by the ancient sage-kings to govern society, not a universal moral order accessible through individual introspection, shifting Confucian concern toward statecraft and away from personal moral cultivation.
Legacy
Sorai's radical historicist method, building on and surpassing Itō Jinsai's Kogaku, profoundly influenced later Japanese Confucian scholarship and the philological methods of kokugaku (nativist) scholars who studied Japan's own classical texts.