As one of the central figures in Islamic studies in Indonesia, Harun Nasution has made a great impact of influence. His model of theology has become a trend-setter and a blue-print in Islamic studies in this country for decades since the 1970’s. As a loyal admirer and follower of the Mu'tazilah, Harun Nasution gave rise to the idea that Muhammad Abduh was a prominent Islamic reformer who agrees with Mu'tazilah doctrine and is even more liberal than the Mu'tazilah. To support his idea, Harun Nasution put forward Hashiyah 'ala al-Sharh al-‘Aqa’id Dawwani li al-Adhudhiyyah by Muhammad Abduh which is the main reference for his famous book Muhammad Abduh dan Teologi Rasional Mu'tazilah. Harun Nasution’s thought needs to be analyzed and reviewed methodologically, in order to make the theological thought always passionate and spared the stagnation and status quo. This study uses the main work of Harun Nasution Muhammad Abduh dan Teologi Rasional Mu’tazilah as its main source in addition to the book Al-Syaykh Muhammad ‘Abduh bayna Al-Kalamiyyin wa Al-Falasifah by Sulayman Dunya. Nasution’s concepts are analyzed through content analysis which consists of data collection, classification, reduction, analysis, and conclusion.