Yongming Yanshou has been defined in previous scholarship as a "Chan Master," though I contend this designation does little to clarify the type of Buddhism he professed. In this thesis I argue that Yanshou viewed the Chan tradition as a movement completely integrated with the scriptural-based Chinese Buddhist traditions of his day, and Chan lineage, a primary feature around which the Song Chan tradition would base themselves, was only of peripheral concern. Instead, Yanshou took the Chan teachings and the scriptural traditions present in the mid-tenth century and organized them all under the "axiom of the one-mind" (yixin zong). This axiom formed the ontological foundation on which all of Yanshou's Buddhist theory and concepts are based, and through an investigation centering around the concept of li ("principle") in the extant writings of both Yanshou and Zongmi, I argue that Yanshou equated the one-mind (yixin) with li in a way that Zongmi never did, and li for Yanshou became synonymous with the axiom of the one-mind as Yanshou's ontic basis. / Thesis / Master of Arts (MA)