The study of literature from the Islamic world in the Western academy has been deeply – indeed, definitionally – influenced by the work of Reynold Alleyne Nicholson, the prolific 20th-century British Orientalist scholar and translator whose English renderings of foundational texts, especially from the Sufi tradition, continue to be read and assigned in the classroom today. Most of Nicholson’s translations (of Rumi or Ibn ‘Arabi, for instance) were of literature written centuries ago; but in 1920 Nicholson published The Secrets of the Self, a translation of Muhammad Iqbal’s (d. 1938) Persian masnavi Asrār-i Khudī, which itself had been published only 5 years earlier. Nicholson’s translation cemented Iqbal’s reputation in the Anglophone world as a pre-eminent poet, philosopher, and Islamic reformer. Iqbal, having studied with Nicholson at Cambridge, appreciated the work, but disagreed with Nicholson on dozens of points of translation in the masnavi from Persian to English, which have been preserved for us in their correspondence. This paper considers some of these points of disagreement as a rare window into a moment in the early decades of translating Islamic texts into English when the author of the “source” language was able to critique the “target” product. Iqbal’s Asrār-i Khudī is a translation project in the sense that it presents a re-interpretation of the literary tradition in whose language (Persian) and form (masnavi) it presents itself; and its translation as an English text occasions a list of perceived errata that illuminate the different levels on which the author and translator understood the poem to be operating. What is Islamic literature for Nicholson and for Iqbal, and how did they see translation as effective (or not) in a historical moment of perceived crisis for the project of Islamic reform? Offering close readings of the translation contentions between the Persian and English of The Secrets of the Self, this paper demonstrates the ramifications that translation choices, even at the level of a single word, can have on debates concerning tradition, modernity, theology, and literary inheritance.