Critical Thinking and Integrated Curriculum: Developing a lens to problematize their relationship in secondary education

«Critical thinking» and «Integrated Curriculum» are concepts that scholars are called to consider when discussing education. In the present paper, we want to emphasize the complexity behind such terms. We will argue for the need to make explicit the conceptual nuances considered when the connections among critical thinking and integrated curriculum are investigated. We contend that only under this condition scholars could factually advance knowledge on how critical thinking and integrated curriculum could be fruitfully combined. We proceed as follows. We begin by presenting the concept of «critical thinking», emphasizing its complexity, which cannot but grow if approaches to teaching it are also taken into account. Next, we focus on the complexity behind the concept of «integrated curriculum». Then we introduce metacognitive skills as potentially game-changing tools in enhancing the portability of critical thinking, and so a sub-item that it is essential to consider in our analyses of connections between the two concepts at hand. We proceed presenting a case study to show in detail an instance of the complexity that characterizes the relations between metacognition skills, critical thinking and integrated curriculum. Finally, we conclude by drawing some possible implications of flattening such concepts that are relevant for the good functioning of our democracies.