Nakagawa Yoichi, a novelist, proposed two literary theories in the Showa period. Both literary theories (Keishikishugiron or "formalism" and Guzenron or "accidentalism"), strongly influenced by scientific thought, have its core in the concept of "Quantum Jump ". Due to this overlap, previous research has not focused on qualitative difference of these two literary theories. However, the difference is important because the latter contains an early sign of Nakagawa's totalitarianism. This paper tries to reveal how the concept of "mechanism", which Nakagawa introduced into his own formalism, was generated, by comparing it with the concept of mechanism in the art world. In addition to this, this paper observes the manner in which Nakagawa's causal theoretic formalism was forced to transform into accidentalism through the controversy over the mechanism with Yokomitu Riichi.