The Decline of Islamic Scientific Thought

The story of Islamic science is not one of unbroken progress but of a complex trajectory that includes a period of remarkable achievement followed by a gradual decline from the fourteenth century onward. Muzaffar Iqbal examines this decline with scholarly rigor, challenging both simplistic explanations and historical mythologies, and situating the decline within its proper complex of causes.

The most commonly cited explanation for the decline of Islamic science is the influence of al-Ghazali's Tahafut al-Falasifa (The Incoherence of the Philosophers), which critiqued Aristotelian philosophy and has been blamed for generating anti-rationalist currents that suppressed scientific inquiry. Iqbal examines this explanation carefully and finds it insufficient. Al-Ghazali himself engaged in sophisticated philosophical reasoning, never condemned all natural inquiry, and distinguished between the philosophical positions he rejected (such as the eternity of the world) and the mathematical and empirical sciences he explicitly endorsed. Moreover, the Islamic scientific tradition continued vigorously for two centuries after al-Ghazali, producing major figures like Ibn Rushd (who wrote a response to al-Ghazali), Ibn al-Nafis (who discovered pulmonary circulation), and the Maragha astronomers. The simplistic 'al-Ghazali killed Islamic science' narrative does not survive historical scrutiny.

Iqbal presents a more nuanced account of multiple converging causes. The Mongol invasions of the thirteenth century destroyed the great cultural centers of the eastern Islamic world — Baghdad fell in 1258, the Abbasid caliphate was ended, and the institutional infrastructure of Islamic learning was severely disrupted. Libraries, madrasas, hospitals, and observatories that had taken generations to build were destroyed. The loss of institutional continuity was devastating for the transmission of scientific knowledge.

The shift in madrasa curricula is another important factor. As Islamic educational institutions became increasingly focused on religious law (fiqh), hadith sciences, and Quran interpretation — at the expense of natural philosophy, mathematics, and medicine — the institutional support for scientific inquiry within the mainstream Islamic educational system declined. This was not a result of any deliberate suppression of science but of the natural prioritization of the religious sciences that were most directly relevant to the life of the community.

Economic and political fragmentation also played a role. The unified Abbasid caliphate had provided both the economic resources and the political stability that enabled large-scale scientific projects — observatories, hospital complexes, translation bureaus. As the Islamic world fragmented into competing dynasties and principalities, the scale of institutional investment in science that had characterized the Abbasid period became difficult to sustain.

Finally, Iqbal examines the internal intellectual shift that occurred when the Islamic scientific tradition encountered what it perceived as the limits of the Greek philosophical framework it had inherited. The great Muslim philosophers and scientists had used Aristotelian categories as the basic framework for natural inquiry, and when these categories proved inadequate to certain phenomena — most notably in astronomy, where the observed motions of the planets increasingly deviated from Ptolemaic predictions — the response in parts of the Islamic world was to question the enterprise of natural philosophy rather than to revise its foundations. The paradigm shift that produced modern science in Europe did not occur in the Islamic world, and understanding why is among the most important questions in the history of science.