Constructivism at the birth of the scientific revolution : a study of the foundations of Qushji`s fifteenth century astronomy

Abstract

This study explores the conceptual foundations and the intellectual structure in the works of ÑAlÉ’ al-DÊn ÑAlÊ QushjÊ (d. 1474) that led to an astronomical model, which research suggests has given a philosophical impulse to the Scientific Revolution in Europe. According to recent historiography of science, it was a specific astronomical model that contained a critical breakthrough for the mathematical foundation of Earth's motion. Until 2005, it was thought that Regiomontanus' (d. 1476) Epitome of Almagest (1496) had supplied this intellectual impetus to Copernicus' revolution in astronomy. But in 2005, it was discovered that QushjÊ, Ottoman Sultan Mehmed II's chief scientist and kalÉm scholar, had authored an earlier Arabic version of this model. This study unravels the new program of science according to the emerging constructivist project of later AshÑarite kalÉm, which was completed by QushjÊ and turned into a comprehensive theory of knowledge to serve as a new foundation for astronomy and mathematics. It shows how in the fifteenth century, constructivist epistemology came to replace Aristotelian realism as a foundation for a new constructive astronomy. Qushjʒs elucidation on constructive semantics in his works on Ñilm al-waÌÑ (science of denotation), as well as his philosophical discussions on mental existence (al-wujËd al-dhihnÊ) in his kalÉm work, SharÍ TajrÊd al-KalÉm (Commentary on Abstracting KalÉm), facilitate this undertaking. The constructive revolution brought forward by Islamic astronomy emerges as the original mathematical revolution against geocentricism. It also provides us with the foundation for a contemporary critique of Copernican heliocentricism, which is currently known to be scientifically untenable. This opens the way for a better understanding of constructivism as a foundation for solving the contemporary challenge of quantum physics. As a result, constructivism, as a foundation for science, had existed in Ottoman Constantinople since at least the fifteenth century. Given that Kant's Copernican revolution of the late eighteenth century was itself a quest for constructivism, its delay until after the Copernican revolution implies that Kant was only attempting to historically unearth the imbedded constructive foundations of the earlier revolution in astronomy. This study helps us answer new critical questions about the historical development of constructivist epistemology, its rise and continuity in time and its early conceptual transmission across civilisational boundaries between Islam and modern Europe.