This study aims to investigate the theoretical foundations of critical thinking based on the perspectives of Roy Bhaskar and Henry Giroux, and subsequently propose a theoretical model for its instruction. To this end, George Bereday’s comparative method—comprising description, interpretation, juxtaposition, and comparison—was employed to analyze and contrast the theories of these two thinkers. Subsequently, a deductive approach was utilized to extract the model based on the established theoretical foundations, while a synthetic method was applied to ensure the internal consistency of this novel integration. The findings indicate that Roy Bhaskar, through his Critical Realism and its specific ontological and epistemological lenses, provides a coherent conceptualization of critical thinking. Key characteristics of his approach include structurality, an emphasis on explanatory understanding, emancipation, and a focus on a stratified ontology. Conversely, although Henry Giroux pays less attention to the deep philosophical foundations of critical thinking—rendering his theories susceptible to criticisms of over-politicization and sloganism—he offers a compelling pedagogical framework. By addressing concrete societal issues through a critical lens and linking critical thinking to social commitment, transformative action, and social justice, Giroux provides a profound understanding of critical pedagogy within curriculum and instruction. In the proposed theoretical model, Bhaskar’s ontological and epistemological frameworks serve as the metalanguage. Consequently, at the level of educational goals and principles for teaching critical thinking, Bhaskar’s philosophical depth is organically synthesized with Giroux’s socio-political and cultural praxis.