This project is an investigation into the role of argumentation in scientific change. A case in point astronomy. Research conducted for more than three decades in the 2nd half of the 20th century by several eminent historians of Arabic and medieval astronomy have radically changed our understanding of its development following the discovery of some important astronomical writings. The work of a group of Arabic astronomers known as the Maragha School (who were working in the Maragha observatory in north-western Iran) provides the evidence for the existence of an intense theoretical research during the 13th and 14th. That research, whose aim was to find alternative models to Ptolemy’s system, led to the construction by Ibn al-Shatir in the 14th of the first nonptolemaic model that contain no eccentrics whatsoever. The sensation of these findings is that they provide valuable information, unknown to modern historians, able to bridge the gap between Ptolemy’s Almagest and Copernicus’s De Revolutionibus. It was found out not only that Ibn al-Shatir and Copernicus systems are identical but that Copernicus used the same technical apparatus developed by the Arabic astronomers three centuries earlier. Besides the intriguing questions raised by the strong similarities between the work of the Maragha astronomers and that of Copernicus, the discovery of a whole new tradition introduced a shift in historical research for it became possible to provide more complete and accurate account of the development of astronomy by focusing on the context of the emergence of the Maragha School. The historical research revealed that the work of the Maragha astronomers has its origin in al-Shukuk or Doubts about Ptolemy, an 11th century book written by Ibn al-Haytham, known in the west as Alhazen for his Optics; the revelation came to confirm what we know from other sources concerning the wider impact of Ibn al- Haytham’s al-Shukuk both in the western and eastern Arabic regions making in effect its release as the major turning point in the history of astronomy. Unfortunately no serious investigation on al-Shukuk was undertaken since the release of the Arabic edition (1971) leaving an important gap in our understanding of the development of astronomy and of the history of science in general.

Our project is designed to complete the works undertaken in the last century by conducting a comprehensive investigation on the development of astronomy in the 11th century centered on the Ibn al-Haytham’s foundational work al-Shukuk. Contrary to his Optics, al-Shukuk is not a book of science but a book about science. What makes al-Shukuk such a landmark in the History of Science is that it shows how change could be brought from within the subject matter, from within a specific tradition the Ptolemaic tradition. This line of research, which will be developed in collaboration with world leading logicians, historians and philosophers, will focus on in three important fields: 1) logical analysis of his argumentation techniques; 2) epistemological investigation of his conception of a scientific theory underlying his refutation; 3) historical investigation concerning the decisive role of Ibn al-Haytham’s al-Shukuk in bringing change from within to a major scientific discipline that was stagnating for centuries. This case study seems to point to a more precise explanation of the development of science that this project aims to explore.