Nakai Riken (?? ??, Riken Nakai, 1732–1817) was a leading academic in the Kaitokudo academy tradition of scholarship.
He was the younger son of Nakai Shuan (1758 d.), one of the Kaitokudo's two founding leaders, and was influenced by his teacher and mentor Goi Ranju.
His intellectualised way of being led to continued engagement with but physical separation from the Kaitokudo.
Much is made of his demeanor reflecting his.
Often stated as analogous to his floating calligraphic style Riken was vastly different in demeanour to his brother Nakai Chikuzan, although their underlying epistemologies, beliefs and degree of tenacious individualism were similar.
They both furthered the work of Goi Ranju and consolidating previous thought around the Kaitokudo school, bringing a level of prestige to the academy.
Like his brother Chikuzan, Riken wholeheartedly denounced Ogyu Sorai and contended that all people have potential, to the extent that "even" commoners could become scholars, while he also denounced religion and superstition.
However, Riken’s particular strain of the dismissal of dreams, and the unverifiable led him to dabble in astronomy, most notably with Asada Goryu.Riken’s scholarship was far broader and is often perceived to transcend the specific question of reconciling the virtue of merchants with contemporary perceptions of merchants.