The Seminal Heart (snying thig) is a form of the Tibetan Buddhist Great Perfection (rdzogs chen) tradition, which itself has been marked by a complex array of contemplative practices that have changed dramatically since its inception in the eighth century right up to present times. A highly innovative central principle in these meditations is the shifting roles of volitional effort and loci of agency at play in their procedures, as well as in the manifest appearances, sensations, and dynamics that constitute the unfolding processes and experiences therein. In addition, subtle and dramatic shifts in transitivity—the directional transfer of energy and locus of agency amongst various agents and patients—are important features, so that understanding these questions of effort/lessness and agency requires paying close attention to the contemplative lexicon of elements and the grammar of contemplation, including moments when there are scripted shifts from procedural techniques to the unfolding logic of experience. This article will focus on the crucial initial formative period of the Seminal Heart tradition—from the eleventh through fourteenth centuries—and offer speculative thoughts about how these contemplative issues were crucial factors in the tradition’s dynamic changes over time.