Critical thinking holds significant importance in the UPSC Mains exam as it enables aspirants to analyze complex issues holistically and formulate informed responses. It helps candidates to evaluate multiple perspectives, leading to more nuanced answers. This skill allows for a deeper understanding of topics and enhances the ability to construct logical arguments. In essay writing, critical thinking fosters originality and analytical depth, which are crucial for achieving high scores. Thus, developing this skill is essential for success in Mains examinations.