This lecture will be an introduction, an overview of the topic now known in many curricula such as the legal system and method; some of you may have known it as Common Law Reasoning and Institutions (as it was once called). The main objective of this work is to examine, through an analysis of relevant case law, how courts interpret and apply primary law in accordance with the obligation of interpretation set out in sections 2 (1) and (4) of the European Communities Act 1972 and section 3 (1) of the Human Rights Act 1998, and to assess the current attitude of jurisprudence towards the traditional concept of parliamentary sovereignty in the light of judicial perception. the duty of interpretation in the above-mentioned provisions. As an essential prelude to the review of the case law on the judicial treatment of the duty of interpretation in the 1972 and 1998 Acts, Chapter 2 of the paper deals with the traditional and Dicey notion of parliamentary sovereignty. This is considered without the effects of the 1972 and 1998 laws. This chapter shows that the courts have considered it their constitutional duty to obey and carry out Parliament`s last will without question. It is observed that n.