Rise of Islam

Western vs Eastern is little more than us vs them, so people will always be shifting the boundries to suit which ever claim they wish. It isn't cut and dry at all.
I'm saying the original East vs West, was the Western Roman Empire, vs the Eastern Roman Empire. So regarding the Eastern Empire and western is not something that should be done. The eastern roman empire is as western as the Ottoman Empire.

What we should be talking about it cultural groups, rather than east & west abstractions. Culturally, Greeks, Egyptians, Syrians and Arabs are in the same group (doubly so in modern times), so Arab architecture naturally is very similar to these groups. This is Roman influence, because Greeks, Egyptians and Syrians were Romans, but Roman is not a synonum for western. Arabs were not influenced by Germanic and Celtic architecture (ignoring Spain)

We discussed this before If I recall correctly. But anyway, I believe the West means Western Europe and its civilization, so I think that saying that Greek civilization is Western civilization is problematic from the historical point of view. It may be safe to say that Western civilization is a Greek civilization, or rather Western civilization is an imitation of Greek civilization. Just because ancient Greeks and their civilization influenced Western Europeans doesn't mean that ancient Greeks were Westerners.

We can safely claim that the Eastern Roman empire was as western as the Ottoman Empire on the basis of the fact that none of them were a product of Western Europe.

Very good point, Reginmund. It's actually a matter of definition, indeed. As we are, professional or amateur, historians, we should define it objectively and historically correctly.