The Avicenna Distinction Between Mental and Concrete Existence

In the 13th century, Najm adin Akatibi Al-Kazwini applied Avicenna's distinction between mental and concrete existence to logic. He was part of a group of pioneering scientists and philosophers gathered around Atousi at the Maraga Observatory. Even though logic in this later period was always done within the framework laid down by Avicenna, his works were not necessarily on the standard reading list.