The term ‘self state’ occupies a contested but productive intersection across neurobiological, clinical, and depth-psychological discourse. Daniel Siegel, its most systematic theorist within the relational-neuroscience tradition, defines self-states as cohesive clusters of neural activity — constellations of feelings, beliefs, intentions, and memories — that achieve enduring continuity through repeated patterning, shifting abruptly as environmental context demands. For Siegel, integration across self-states is the developmental and therapeutic challenge: without it, the plurality of the self risks fragmentation rather than enriching complexity. Richard Schwartz, working within the Internal Family Systems framework, employs a related but distinct usage: the ‘Self-state’ marks the experiential condition of being led by the Self rather than by protective parts, characterized by the so-called eight Cs — calm, curiosity, clarity, compassion, confidence, creativity, courage, and connectedness. Here the Self-state is not merely one configuration among many but the optimal, essentially undamaged ground of consciousness. Antonio Damasio contributes a neurobiological stratum with his ‘core self state,’ locating it in protoself dynamics mediated by brainstem and insular cortices. Pat Ogden’s sensorimotor framework bridges these registers, distinguishing trauma-sequestered self-states from the more permeable internal conflicts of non-traumatized clients. Taken together, the corpus reveals a fundamental tension: whether self-states are equivalent, context-dependent configurations of a plural mind or whether one state — variously named Self, core self, or integrated self — carries normative priority.