Didn't say that the so-called Dark Ages were caused by a single factor, but there was a primary factor and that was the jihadist invasions known as the Islamic conquests. I suggest you look over these works since they go into more detail:
As for the treatment of minorities, are you familiar with treatment of dhimmis under Islam? You can examine these texts for more: http://www.amazon.com/Islam-Dhimmitude-Where-Civilizations-Collide/dp/1611472369. The treatment of minorities under Islam was always in flux depending on the location and who was in charge. Jews may have been treated better than the Christian and pagan populations of Europe, but there were intermittent persecutions against them too, just as there were persecutions against Christians.
As for trade, read what happened to the papyrus supply being cut down and how it affected literacy in Europe. This was noted by historian Henri Pirenne in the 1930s.
As for 1453 and later, that is hundreds of years after the events I'm discussing, so it's not relevant here.
Wow I didn't know about the fact that Islam cut of trade with the west, I wasnt familiar with this thanks for showing it. But I highly doubt that was as big of a problem as the other bigger problems. Look at the fall of the Western Roman empire and the barbarians that invaded the north of Europe and destroyed any traces of civilization I think that setback Europe worse than the end of trade with the Mediterranean. Then look at what Christianity did to Europe. I think that the Church hindered Western development the most. They were intervening with the affairs of most European rulers and they caused a lot of in fighting between the Europeans. The west lost most of its technological advances by the rise of barbarians. And then when you look at science I think the Arabs at the time did very good by preserving Roman and Greek technology that was lost with these invasions, and they even made significant improvements themselves.
I know about the Dhimmi's and I actually taught it was a good thing, If you look at the conditions of that time many people were slaughtered in the rest of the world, or forced to convert to a different religion. The Jizra and the use of Dhimmi's prevented any of this. And I agree that ofcourse the treatment of minorities differed from leader to leader, but with the standards of that time I think it was better than for example the Spanish inquisition or other ways of dealing with religious minorities(not implying Muslims were saints or anything).
And with the info you showed me I can agree with you that Islam was a factor hindering the development of Europe in that time.
