In the mid-Sassanid era, an influx of knowledge came to Persia from the West in the form of views and traditions of Greece which, following the spread of Christianity, accompanied Syriac (the official language of Christians as well as the Iranian Nestorians). The Christian schools in Iran have produced great scientists such as Nersi, Farhad, and Marabai. Also, a book was left by Paulus Persa, head of the Iranian Department of Logic and Philosophy of Aristotle, written in Syriac and dictated to Sassanid King Anushiravan.