My ultimate point therefore, was that there is no more validity in the complaint amongst the Chalcedonians, regarding a Copts' claim to Orthodoxy, or a Syrians' claim to Orthodoxy, any more than a Greeks' claim to Orthodoxy or a Russians' claim to Orthodoxy. The Coptic Church officially goes by the name "The Coptic Orthodox Church", and not the "Coptic non-Chalcedonian Church" or the "Coptic Oriental Orthodox Church".
Yes, I understand. The Assyrians go by the name "Orthodox" too, and they are Nestorian. The name "Orthodox", and "Catholic", and "Christian", can be used by anyone, and most people are willing to loosly apply those names to anyone who wants them, but ultimatley those names are only properly attributable to the one and only true church. Only the true Church with the true faith has validity, no matter if most of the people in the world agree with her or not. There is no such thing as equal validy of differing faiths because only one faith is the faith of God, and all the others are inventions of men.
But the issue here is, that in presupossing his own faith to be "THE Orthodox faith" he is attempting to argue the invalidity of the Coptic Church laying claim to be of "The Orthodox Church".
Exactly. Orthodox ("Diophysites") don't believe anyone but them can lay claim to the title "Orthodox", or "Catholic", or "True Church", or even "Christian" in the true sense of those words. Nobody can properly be called a Christian except those who have been Baptized in the Church. We in fact do believe that the Coptic Church is "invalid"; you shouldn't be offended by that, you should consider it only natural. And I expect that you consider me "not orthodox" since I don't share the same faith as you.