As recently noted by the "Shrine for the Holy Whapping," a Catholic blog, Aquinas quoted with approval, the following (link to source):
"We believe that the bodies of the saints, above all the relics of the blessed martyrs, as being the members of Christ, should be venerated in all sincerity" and "If anyone holds a contrary opinion, he is not accounted a Christian, but a follower of Eunomius and Vigilantius." (citing De Eccles. Dogm. xl)
Lay Catholic Dave Armstrong has asserted: "I would note that the official Catholic position is to acknowledge Protestants as Christian brothers, whereas many Protestant groups either are officially anti-Catholic or contain within themselves a strong legacy of anti-Catholicism which is then passed down almost unconsciously. " (source)
Let me be clear: the body (in whole or in part) of no Christian whatsoever should receive religous veneration of any kind, whether alive or dead. Furthermore, religious veneration of corpses is open necromancy (in the broad definition of that word). Nevertheless, that does not mean that we cannot treat corpses with respect, or that we cannot hold funerals, etc. Thus, religious worship (such as Catholic veneration of relics) is to be distinguished from non-religious consideration. In view of these statements, it should be apparent that I hold a contrary position to that of Aquinas expressed above. According to Aquinas' standard, I should not be accounted a Christian.
On the other hand, Armstrong broadly defines Christianity this way: "[A]nyone who is a trinitarian and who adheres to the Nicene Creed is (doctrinally) a Christian (that is basically the official Catholic position on other Christians)" (source - including all bracketed material).
So, now the question is this:
1. Is Aquinas out of touch with the Official Catholic Position?
2. Is Armstrong out of touch with the Official Catholic Position?
3. Has the Official Catholic Position changed? (If so, when and by whose authority?)
4. Are Aquinas and Armstrong somehow reconciliable? (If so, how?)
5. It doesn't matter / no one can understand Catholic theology, except people who agree with me / some similar cop-out
6. Your views are not contrary to those of Aquinas.
That last option seems utterly implausible.
Option 5 is self defeating.
Option 4 doesn't seem possible, but I'm open to attempted explanations.
Option 3 is my thought as to the best guess - with the Vatican II era being the place where the tide shifted in favor of people who think it is a species of necromancy to venerate the "relics of saints."
Option 2 is presumably the answer that traditional Catholics, especially sedavacantists, would give.
Option 1 would take a great deal of gumption, but perhaps someone will try to make that claim.
NOTE: Although I enunciate very quickly the objection to veneration of alleged relics, this is not the post for that debate. This post is questioning whether modern Roman Catholicism (and/or Dave Armstrong) defines Christianity the way that Aquinas did.