<p>This paper addresses the longstanding ambiguity of terms such as <i>self</i>, <i>identity</i>, and <i>subjectivity</i> in psychology and philosophy. Rather than adding yet another definition, it introduces Metaqualia Theory (MTQ) as a structural grammar that generates these notions as derivative effects of the Q–M–T cycle: <i>Qualia</i> (Q) as raw experiential material, <i>Metaqualia</i> (M) as interpretive stances, and <i>Transduction</i> (T) as the stabilization of experience in social and communicative fields. Within this framework, “self” is not an intrinsic entity but the retrospective label applied when an active M is stabilized through T; “identity” denotes the socially recognized continuity of such stabilizations; and “subjectivity” is the conventional name given when Q is framed by M. MTQ thereby systematically distinguishes between self, identity, and subjectivity, while avoiding homuncular explanations. It also differentiates itself from dialogical and constructivist models by specifying structural conditions under which these labels arise, rather than assuming them as givens. The result is a coherent conceptual lexicon that integrates existing insights without collapsing into definitional disputes. MTQ thus offers psychology a grammar of consciousness capable of clarifying key terms and situating them within a unified structural account.</p>