(continued from: Aristotle and the Science of the Church )
While the Church's maintained control of the knowledge of the world, and prohibited most non-scripture studies, alchemy was the exception. The study of alchemy did not challenge the Church’s view of the world and therefore, could be practiced.
For over 900 years, from about 500 to 1400, philosophers in Western Europe, surrounded by a cloak of secrecy, predominantly occupied themselves with the search for the mythical philosopher’s stone (the substance that would transform everyday material to gold, and produce the elixir of immortality). Many practical techniques, like distillation, were developed during this period, but the understanding of the world and its working remained unchanged and unchallenged.
During this Dark Age of European science, Arab science flourished. Arab philosophers cultivated an intellectual environment that encouraged the sharing of ideas, open discussion and debates. The scientific methodology they had developed was based on experiments to distinguish between competing scientific theories, citation, peer review and open inquiry. This framework, which is the base of all modern science, led to many invaluable breakthroughs in all areas of science: chemistry, physics, optics, astronomy and mathematics.
It was the fall of Constantinople (now Istanbul) that brought Arab science to the attention of the Western European philosophers. Constantinople, the capital of the Byzantine Empire, had been a major intellectual center. Its conquest by the Turks in 1453 led to an exodus of scientists and philosophers to Western Europe.
Coinciding with the recent invention of printing by Gutenberg around 1450, the scientific knowledge these scholars brought with them (including Arab science) became widely available, and readily absorbed by western philosophers. The seeds for a new worldview were planted in a fertile soil, and science of the stars – the oldest of all natural sciences – was the natural place for them to germinate.