 Back in Persia, came the advent of the Safavid dynasty in the 16th century CE, the founders of which were practicing Sufis affiliated with the grand Sufi master, Ṣafī al-Dīn Ardabīlī (1252–1334 CE). There the use of Sufi doctrine, philosophy, and asceticism within a single philosophical paradigm reached its pinnacle. The most important issue of what came to be called the “School of Isfahan” was the “reality of being” (ḥaqiqat al-wūjūd ) as opposed to the “concept of being” (mafhūm al-wūjūd).