The world has seen perhaps four or five great "center" civilizations, among them China. Two of these ancient, long-lived civilizations were Egypt and Mesopotamia-Assyria-Babylon-Persia (the name and capital changed, but it was essentially the same civilization reborn).
Islam has the distinction of having destroyed two of these great, long-enduring world civilizations. In the process, no doubt they learned a few things from captured libraries and slaves who were more civilized than their captors. But to all appearances the number of great, original Muslim thinkers is pretty small.
Pretty much the same argument could have been made of the Germanic barbarians who conquered Western Europe. They brought little original, at least in material things, to Western civilization. Instead, for most of a thousand years they attempted poor imitations of the Greek and Roman civilizations that preceded them.
In 1400, Western civilization had climbed back to a point roughly equal to the Islamic, Mogul, Chinese and Japanese civilizations. The interesting point is not that Islamic civilization stagnated at that point (as did the others), but rather that Western civ entered a 600 year period of amazing innovation and expansion which continues today.
The Moslems did do incredible work in creating a synthesis of Greek, Roman and Persian art, architecture and science and were significantly ahead of Western Europe from about 800-1400 CE.
Let's not get too cocky. Western civ can decline and fall as others have before it. Not because it's overthrown by outsiders, but from its own decadence.