The most effective and pertinent subject in the entire UPSC curriculum is ethics case studies  GS-4, which may be used to test one's ethical principles. This is a fundamental module in the UPSC curriculum that assesses a candidate's ability as well as mindset, allowing one to determine how they will approach ethical case studies. As all of these ethics case studies apply to the real world and are connected to all of the social events taking place in society, one must have a receptive attitude towards them because learning exclusively from books is not a suitable or relevant course of action.