The xin is most commonly characterized in pre-Qin texts as a locus of thought and decision making, sometimes linked to cognition or moral emotions like worry or compassion, but primarily concerned with what we could very well call “reason.” Especially once we enter the Warring States, it is represented as at most only vaguely located in the body, with an extremely tenuous relationship to both the body itself and other bodily parts. It is reasonable to describe the xin as metaphysical, somehow free of the limitations of the physical world. Focusing on the term xin (heart, heart-mind, mind), this chapter uses qualitative textual analysis to make the case that early Chinese texts were written by people who embraced, at least implicitly, a “weak” form of mind-body dualism. This includes the idea that the mind is at least somewhat immaterial, qualitatively different from the other organs, and the seat of reason, free will, and the individual self.