The Decline of Science in Late Antiquity: Causes and Consequences

The causes behind the marked decline of natural philosophy and scientific inquiry at the end of the Greco-Roman era remain actively debated by historians. Disagreement exists even regarding the timeline, with some dating the downturn from 200 BCE during the Hellenistic era, while others identify a later onset after 200 CE. Although scientific activity did not cease entirely after the second century CE, it notably lost momentum and originality during late antiquity. Intellectual endeavor shifted predominantly from the discovery of new knowledge toward the preservation and compilation of existing learning, exemplified by figures such as Oribasius in Constantinople, who produced a massive seventy-volume medical compendium in the fourth century. The underlying spirit that animated earlier Greek science gradually faded, giving way to increasing skepticism, a decline in preservation efforts, and the rising influence of magic and superstition.

A prominent explanation for this decline highlights the lack of a clear social role for science in the ancient world. Scientific pursuits were poorly socialized and institutionalized, lacking a stable ideological or material foundation within society. No professional employment existed for individuals acting specifically as scientists or natural philosophers. Furthermore, the separation of science from mainstream philosophy during the Hellenistic period further undermined any potential societal function for the scientific enterprise, leaving it without a secure niche.

A related economic explanation centers on the separation of science and technology in antiquity. The prevalence of slavery and cheap human labor, combined with a prevailing ideology that deemed natural knowledge unsuitable for practical application, removed key incentives for employing scientists or seeking useful outcomes from abstract theories. By systematically excluding the potential utility of scientific understanding, ancient society effectively undermined any rationale for providing sustained social support or resources to scientific endeavors, stunting its development.

The flourishing of various religious cults and sects in late antiquity also significantly weakened the authority and vitality of traditional scientific traditions. Cults such as those dedicated to Demeter, Isis, and Mithraism offered intellectual and spiritual competition, often promoting anti-intellectual or revelatory approaches to knowledge. The most successful new religion, Christianity, achieved extraordinary institutional success following Emperor Constantine's conversion and its establishment as the official state religion in 391 CE. While experts debate its precise impact, the early Christian church, with its theological focus on revelation and the afterlife, often displayed hostility, skepticism, or indifference toward pagan culture and scientific inquiry into nature.

The institutional rise of the Christian church also created a practical drain on intellectual talent. As the church established a formidable bureaucratic and administrative presence across society, it offered viable careers and employment. This effectively redirected intellectual energy that might previously have been recruited by centers of learning like the Museum at Alexandria or directed toward scientific pursuits, further depriving science of its human capital.

Concurrently, major centers of learning suffered devastating blows. Alexandria and its intellectual infrastructure endured repeated damage from the late third century onward, including destruction during Roman reconquest, alleged book burnings by Christian vigilantes, and the symbolic end of the Museum itself after the murder of the pagan scholar Hypatia in 415 CE. Later, the initial Islamic conquests damaged what remained of the Library at Alexandria, while in 529 CE, Emperor Justinian ordered the closure of the Platonic Academy in Athens, severing another direct link to classical philosophy.

The political and military collapse of the Roman Empire further catalyzed the decline, particularly in the Latin West. Following the empire's division, the Western Roman Empire succumbed to barbarian invasions, epitomized by the Visigoth sack of Rome in 410 CE and the deposition of the last Roman emperor in 476 CE. This precipitated a profound civilizational disruption and discontinuity. In contrast, the Hellenized East Roman Empire, or Byzantine Empire, centered on Constantinople, maintained greater continuity until it too faced severe pressure from the ascendant Islamic Arabs in the seventh century.

The plight of learned individuals in this transitioning world is poignantly illustrated by Boethius (480-524 CE). A Roman senator and exceptional inheritor of the classical tradition, he served the Ostrogoth king Theodoric. Before his execution, Boethius worked desperately to preserve ancient knowledge, translating Aristotle and Euclid and writing handbooks on arithmetic, geometry, astronomy, and music. His efforts, along with those of later compilers like Cassiodorus, Isidore of Seville, and the Venerable Bede, ensured the passage of mere fragments of Greek science into the early medieval Latin West.

The early Middle Ages in Europe were characterized by an utterly sorry state of learning. Literacy and knowledge of Greek virtually disappeared. The profound intellectual poverty of the period is starkly demonstrated by examples such as Isidore of Seville apparently believing the sun illuminated the stars, and eleventh-century scholars being unable to comprehend the basic geometric theorem that the interior angles of a triangle equal two right angles. The era of autonomous Greek science in antiquity had conclusively ended, and its eventual revival in Western Europe centuries later would require entirely new social, economic, and intellectual conditions.