Recent public opinion surveys show a majority of Americans see ``little'' or ``nothing'' to admire in Islam or the Muslim world. Seventy percent say Islam has nothing in common with their own faith, an increase from 59 percent two years earlier.

Those with the strongest anti-Muslim views rely most on the media -- not personal experience, travel or study -- for their information about Islam. Nor is the nation's educational elite any less immune to the power of the predominant media narrative of Islam as irrevocably violent, anti-modern, anti-women and anti-democratic.

This same narrative dominates every aspect of the way we think and speak about Islam. It shapes how we listen to what Muslims say and how we interpret what it is they do. As such, it exercises a corrosive effect on everything from politics and theology to international relations, human rights and national security policies, including today's ``war on terrorism.''

This has left the West intellectually and politically unable to respond successfully to some of the most significant challenges of the early-21st century -- the rise of Islamist political power, the more narrow emergence of terrorism in the name of Islam, tensions between Western social values and multicultural rights on the part of growing Muslim immigrant populations.

Often overlooked in discussions of contemporary relations between Islam and the West are the broad historical, intellectual and philosophical ideas that literally dictate how we as Westerners apprehend the world of Islam and the Muslims. If we take just one obscure corner of this vast field -- that of the history of medieval science -- we may be able to learn much about our views of Islam, and about ourselves as well.

Our starting point is the 11th century, the era of the Crusades. Before that, Christian Europe looked upon the Muslims with indifference; they were a nuisance to shipping and coastal settlements, but they were certainly not seen as an existential threat. All that changed in the run-up to the First Crusade, proclaimed in 1095. Now, a distinct portrait of Islam began to take shape in the medieval Western mind, with the practices and beliefs of the Muslims conceived as mirror-opposites of self-evident Christian virtues.

Where Christianity stands for love, Islam is a religion of violence; where Christ stands for truth, Muhammad and the Quran stand for falsehood; where Christians are chaste, Muslims are sexual deviants. Over time, these notions acquired a number of corollaries: Muslims are backward, and fearful of modernity; the West is rational, Islam is irrational and fanatical. In an observation as apt now as when it was first advanced 900 years ago, one chronicler of the First Crusade acknowledged that it was not important to actually know anything about Islam in order to attack it: ``It is safe to speak evil of one whose malignity exceeds whatever ill can be spoken.''

One of the most salient aspects of the medieval history of science is the relationship between sacred and profane knowledge. Under the influence of Augustine and other Church Fathers, the early Christian world saw no reason to explore what the Ancient Greeks had called ``the nature of things.''

Yet, things looked quite different to the Muslims. Arab scholars found divine support for science in the Quran, the revealed Word of God. A number of verses refer to the order inherent to God's universe and to man's capacity to exploit this order for his own needs, such as keeping time. Elsewhere, the Quran advocates the use of God's creation for orientation amid the featureless deserts and navigation across the oceans. By one scholar's count, the Arabic word for ``knowledge'' (ilm) and related terms comprise almost 1 percent of the Quran's 78,000 words and are among its most frequently used terms, a feature that highlights just how important the concept was for the first Muslims.