Since Halil İnalcık's classic The Ottoman Empire: The Classical Age (1973), the received view amongst historians has been that Ottoman scholars lost interest in the rational sciences after around 1600, largely as an effect of the rise of the puritanical Kādīzādeli movement. In the present article, I argue that there was in fact no decline of interest in the rational sciences amongst seventeenth century Ottoman scholars. On the contrary, interest in logic, dialectic, philosophy and rational theology seems to have been on the rise. Sunni Persian, Azeri and Kurdish scholars fleeing Safavid Iran brought with them new scholarly works in the rational sciences and gained a reputation as accomplished teachers. The number of Ottoman colleges in which works on the rational sciences were studied and taught also seems to have risen dramatically in the course of the 17th century.