Illustrative diagrams, their functions, and where they fall in the spectrum of graphic representation of cosmological ideas was discussed as a general survey by Ahmet Karamustafa in a chapter titled “Cosmographical Diagrams” in the multi-volume History of Cartography. The scope of his survey on Islamic cosmographical diagrams includes ones that appear in Arabic, Persian, and Turkish texts and in the cultural context of the Islamicate medieval and early modern periods. Karamustafa argued that in Islam there had been a lack of a continuous tradition of cosmological speculation that developed diagrams illustrating major features of a universally accepted Islamic cosmology. While that assessment may be true, early modern Ottoman Sufi poets/authors—in particular, members of the Khalwatiyya and its offshoots—and their literature surprise us with an unexpected phenomenon: elaborate narratives with complex diagrams, letters, numbers, illustrations, and tables with esoteric and mystical content. Tentatively calling them “mystical/visual cosmologies”, in this presentation, I will examine the use and utility of letters, numbers, and diagrams in a number of unpublished Ottoman Turkish manuscripts written by thus far unknown Sufi authors with Khalwati affiliations. I hope to demonstrate that while Ibn al-Arabi’s influence is clear in the realm of “letters”, a consideration of the influence of the representatives of the Ikhwan al-Safa in the Ottoman context is necessary for a better understanding of the use and function of the “numbers” and their complex representations in elaborate diagrams and illustrations that surface in these texts. Most of these texts use Arabic, Persian, and Ottoman Turkish interchangeably to depict textual and visual content. My goal is to investigate “mystical and visual cosmologies” in historical and textual context to see if such works can be understood as a type of “new-learning” in the early modern Ottoman world—one that unites Neo-Platonic and Aristotelian “scientific” knowledge, Islamic mysticism, "occult" sciences and Qur’anic teachings.