The primary ability that modern pedagogy strives to develop is critical thinking; its development allows considering the ideas in innumerable ways. This paper explores how these competencies can be improved with the help of Content Based Instruction (CBI) among undergraduates by incorporating real texts (i.e. novels and historical excerpts) into language courses. Through real material, the students are forced to apply high-order thinking processes, such as analysis, assessment and inference. The results show that indeed addition of content rich modules does increase reading and critical-thinking comprehension. Both pre-test and post-tests in history and literature courses showed a systematic increase in these cognitive domains and the quotations in interviews confirm that students are aware of the importance of struggling with complicated information. The paper, therefore, finds that the inclusion of subject-related material into the process of language acquisition is not a favorable additional item but an efficient methodology that fosters language proficiency and provides the learners with the critical-thinking abilities that are necessary to operate in the information-rich environment.