There is a reason these Western terms have Arabic roots: Between the eighth and 12th centuries, the Muslim world, whose lingua franca was Arabic, was much more creative than Christian Europe, which was then in the late Middle Ages. Muslims were the pioneers in mathematics, geometry, physics, astronomy, biology, medicine, architecture, trade and, most important, philosophy. To be sure, Muslims had inherited these sciences from other cultures, such as the ancient Greeks, Eastern Christians, Jews and Hindus. Still, they advanced those disciplines with their own innovations and transmitted them to Europe.

Why delve so deep into this much-forgotten history? Because there are lessons for both Muslims and non-Muslims.

Among the latter are Western conservatives, who are passionate about protecting the legacy of Western civilization, which they often define as exclusively “Judeo-Christian.” Of course, Western civilization does have a great accomplishment worth preserving: the Enlightenment, which gave us freedom of thought, freedom of religion, the abolition of slavery, equality before the law, and democracy.

Those values should not be sacrificed to the postmodern tribalism called “identity politics.” But Western conservatives retreat to tribalism themselves when they deny the wisdom in, and the contributions of, sources that are not Judeo-Christian. The third great Abrahamic religion, Islam, also had a hand in the making of the modern world, and honoring that legacy would help establish a more constructive dialogue with Muslims.

Of course, we Muslims ourselves have a big question to answer: Why was our civilization once so creative, and why have we lost that golden age?

Some Muslims find a simple answer in piety and the lack thereof, thinking that decline came when Muslims turned “sinful.” Others assume that the early majesty can be traced to mighty leaders, whose reincarnations they hope to see again. Some find solace in conspiracy theories that blame enemies outside and “traitors” within.

Here is a more realistic explanation: The early Islamic civilization was creative because it was open-minded. At least some Muslims had the urge to learn from other civilizations. There was some room for free speech, which was extraordinary for its time. That allowed the work of towering Greek philosophers such as Aristotle to be translated and discussed, theologians of different stripes to speak their minds, and scholars to find independent patronage. From the 12th century onward, however, a more uniform and less rational form of Islam was imposed by despotic caliphs and sultans. So Muslim thought turned insular, repetitive and incurious.