One of the most striking aspects of Natsume Sōseki's Theory of Literature (Bungakuron, 1907) is the initial interdisciplinary move to generate a model of moment-by-moment literary experience, replete with graphs, formulas and tables, with reference to what was for him the latest in contemporary clinical, experimental psychology. Whatever other rhetorical, philosophical and aesthetic concerns are at issue in its sprawling length, this initial suggestion of a natural scientific account of the object remains a powerful methodological move. This paper will address the questions of why and in what sense Sōseki's theory can be considered a scientific theory and what type of psychology is at stake in the initial waveform model and (F+f) formula. With reference to William James and contemporary developments in neuropsychology, it will be argued that the rise and fall of an antithetical behaviorist paradigm as the dominant mode of psychological explanation has allowed Sōseki's theory to emerge at the other end of the twentieth century with increased relevance, in an even tighter relation to growing knowledge about the relation of thought processes to the heterogeneous architecture of the brain. By posing the problem of literature in a way that is comprehensible to the sciences that deal with related issues of the mind, Sōseki provides a model for interdisciplinary research that is still challenging today.