By reviewing the literature of logical positivism in the psychology of traditional Chinese medicine (TCM), the author posits that current thinking remains limited within the framework of subject-object dualism common in mainstream psychology, a framework that strongly contradicts the essence of TCM. As such, the psychology of TCM has deviated from cultural subjectivity. Based on personal reflections of her own academic profile and contexts, the author argues that only by developing the psychology of TCM within cultural subjectivity can psychology develop toward a knowledge system that transcends this limiting framework. By reviewing six psychology research paths as they have developed in Taiwan over the past three decades, the author outlines three sufficient and necessary conditions for “Subjectivity Psychology”: 1. researchers should be situated within contexts of culture/society/history and commit themselves to the situation; 2. knowledge systems should be based on ontology, epistemology and methodology; 3. knowledge should be emancipative to support and promote subjectivity. Based on these conditions, the present essay reconsiders the properties and production of knowledge within the psychology of TCM, identifying a “Subjective Psychology of TCM” that is grounded firmly in philosophical traditions of ontology, epistemology and methodology. Namely, the present essay argues for a “Subjective Psychology of TCM” that is, ontologically speaking, a strong, updated version of psychophysical parallelism; a psychology that is epistemologically grounded in inter-subjectivity and praxis-oriented approaches, wherein knowledge is produced through practice, and one in which the methodology is fundamentally action research and critical praxis. As such, this essay posits that a truly subjective TCM and Psychology of TCM must utilize the tacit knowledge-in-action, reflection in action, and reflection on action approaches of action research, and should therefore regarded as a branch of Action Science.