Given boasting talks in Imam Ali (PBUH)’s Nahj al-Balagha, it seems necessary to explore them according to most recent methods of psychological analysis to ascertain whether self-praise can be attributed to the Islamic-spiritual leader. The category of self-praise contains many features of narcissism. This study first provides a psychological analysis of the boasting talks and then looks at them from a linguistic viewpoint. The research results make a substantial contribution to knowing the character of Imam Ali (PBUH) and interpretating old texts related to theosophical-historical issues. It belongs in the domain of historical and calculative psychology which examines behavior, the mind, and effects of historical, social and cultural factors. First, using the ‘representation of conceptual structure’ which is a new method of processing natural language aimed at linking natural language with psychometric measures, the study explores the text of Nahj al-Balagha and the convergence between it and Ruskin and Terry’s Narcissist Personality Inventory (NPI-40) which provides the most commonly used criteria for measuring narcissism in the literature of social and personality psychology. In addition to measuring the fulfilment of the criteria of narcissism by Imam Ali (PBUH)’s speeches in the text of Nahj al-Balagha, this study determines the regression between the text and seven sub-measures, and through exploring the text of Nahj al-Balagha has interpreted different aspects of the measure. According to the research statistics, Imam Ali (PBUH) does not show a narcissistic personality in Nahj al-Balagha, and sub-measures of exhibitionism and authority have the highest rate compared to other sub-measures. Third to these is self-sufficiency, and vanity and entitlement have the lowest rate. Furthermore, narcissism sub-measures in Nahj al-Balagha have the lowest rate in Imam Ali (PBUH)’s negative and reproachful statements, and the highest rate in his speech containing subjects of ‘rightfulness’, ‘praise and condemnation’, and ‘war’