In the surviving works of the two rationalist currents of the Ḥilla theological school — rationalism inclined toward Muʿtazilism and rationalism inclined toward philosophy — imāmate was defined as "general leadership" (riʾāsa ʿāmma). Different explications of this dominant definition were offered in these two periods of rationalism. Employing a descriptive-analytical method, this study asks: How were the elements of this dominant definition explicated in the theological works of the rationalist current of the Ḥilla school? Findings show that the definition of imāmate as general leadership entered the Ḥilla theological school from the later Muʿtazilites, was introduced with modifications as the real definition of imāmate (ḥaqīqat al-mutasharriʿa), and with the introduction of philosophical terminology into kalām during the second period of rationalism, received a different explication. Regarding imāmate as a real definition, while diminishing its station, it is incompatible with certain Imāmī beliefs concerning the Imam's station. Likewise, construing imāmate as a category of relation (iḍāfa) leads to a philosophical contradiction.Keywords: Ḥillah School, Imamate, General Leadership (al-Riyāsat al-'Āmmah), Mu'tazilah, Philosophy.