Originally Posted by Starman
Some professors enjoy being enigmatic. Perhaps your professor is trying to say that Islamic governments tended to be tolerant of other religions within the conquered territories. For example, in Muslim Spain, Jews and Christians were allowed to worship as they pleased and were respectfully referred to as people of the Book. This tolerance ceased when professed Christian monarchs, Ferdinand and Isabella gained control of the former Muslim territory and began to require forced conversions of both Jews and Muslims to their form of worship under the threat of expulsion from the country.
BTW
What does your professor say when students argue against his statement?