The literature of esoteric exegesis among various Muslim communities is vast and extremely diverse. The Ismailis (with all their diversity and various branches) represent one piece of this extremely fascinating puzzle. There are, however, a number of misleading assumptions about Ismaili taʾwīl which has led to erroneous conclusions when studying Ismaili literature. Some of these assumptions emanate from taking from granted the particular genre of esoteric exegesis from one period and then generalising it to other periods of Ismaili history. In the following paper, drawing on specific examples of Qāḍī al-Nuʿmān, al-Muʾayyad fī al-Dīn al-Shīrāzī, Muḥammad al-Shahrastānī and Naṣir al-Dīn al-Ṭūsī, I will demonstrate that the genre and language of taʾwīl among Ismailis has been fluid. Their methodology has evolved as well as their language. As a result, the output of this exegetical engagement with the Qurʾān among Ismailis varies significantly to the extent that if one compares an early esoteric exegetical Ismaili work with another from a later period, it might be difficult to consider both belonging to Ismailis. Elements of Neoplatonic views and later on different Sufi approaches alongside a rational perspective have all to some extent appeared in different genres of Ismaili taʾwīl. I will also be arguing that in Ismaili literature there is a common rational underpinning for these engagements alongside belief in the centrality of the guidance of Shiʿi Ismaili Imams for providing this esoteric exegesis. As such, rationality and the authoritative voice of the Ismaili Imams converge side by side in the Ismaili genres of esoteric exegesis. Both of these, commitment to rationality and the voice of Ismaili Imams, have evolved and shifted over time; as a result, we deal with sometimes diverging examples in different historical periods of Ismaili history. This paper will attempt to offer these examples and provide measures of how to tell them apart while locating them in the broader context of Ismaili esotericism.