TSUDA was the first person who criticized literature regarding the process of coming into existence of the kojiki and Nihonshoki in earnest, and concluded that the Japanes had to understand that description concerning Emperor Jimmu did not reflect any fact in the Yayoi period, but were mostly written as part of Japanese Mythology in order to justify the ruling of Japan by the Imperial Family, taking advantage of mythology and folklore.
津田は記紀の成立過程に関して初めて本格的な文献批判を行い、神話学、民俗学の成果を援用しつつ、神武天皇は弥生時代の何らかの事実を反映したものではなく、主として皇室が日本を支配するいわれを説明するために述作された日本神話の一部として理解すべきであると断じた。