This article investigates the intertwined constructs of metacognition and self-regulation as they emerge in the works and theories of James, Piaget, and Vygotsky. To coordinate this exploration, we use an interpretive framework based on the relation of subject and object. In this framework, James's perspective on metacognition and self-regulation is aligned with the Self, Piaget's with the other and object, and Vygotsky's with the medium or agency of language. We explore how metacognition and self-regulation function within the realm of human behavior and development as described in the works of each of these theorists. Key questions or issues that emerge for current research are outlined, and the limitations and benefits of each theorist's perspective vis-a-vis metacognition and self-regulation are discussed.