No, I'm not playing devil's advocate
I don't believe that Moses wrote all of the first five books of the Bible (including the stuff that happened after his own death); I still consider them the "book of Moses." I don't believe that David wrote all the Psalms; I still consider them the Psalms of David. I don't believe that the Apostles wrote the Apostolic Canons; I still think they are the teachings of the Apostles; I don't believe that Dionysius the Areopagite wrote Mystical Theology and the other works attributed to him; I still think those works are perfectly Orthodox and not merely semi-Orthodox, neo-platonic works. While I don't have any quotes to back this up, I don't think the Fathers disagreed with this view of things. If and when I do come across quotes--either evidencing or contradicting my position--I will post them here.
Until then, what's the fear in discussing (and if you're worried about the non-Orthodox, well, most egg-heads would like to know that this type of thing is being discussed)? Hebrews is a fine example: maybe Paul wrote it, maybe he didn't, the Church wasn't sure. Same thing with Revelation, most thought it was St. John the Apostle (the one the Lord loved), but some other Fathers disagreed. Shall we call those Fathers who disagreed fools? There were lots of other disagreements over authorship then, even as now. I believe that if something is accepted by the Church--especially by all, everywhere, and from ancient times--then it is accepted, regardless of whether we are perfectly certain who wrote it. Consider that even some of our Scriptural books (e.g., Tobit) were written by unknown authors. It doesn't matter whether Mystical Theology was written by St. Dionysius the Areopagite, or someone who was a 5th century Christian philosopher. That the end of Mark, or that certain other portions of Scripture were added later seems agreed upon by most (even many traditionalists)--that doesn't make the "additions" unimportant or of lesser value. Does the Liturgy of St. John Chrysostom have less value because it was added to later on? How about the Canons of the 7 Ecumenical Councils?
It is not my ignorance that I fear, Joanna. I will always be ignorant. What I fear is those times (which are often) when, in my pride, I forget that I am ignorant. I need to be humble. But sometimes humility means admitting that maybe I don't know as much as I'd like to think I know. Maybe I don't know for sure who wrote Mystical Theology, and maybe that's a good thing, as it is a curb against my pride: it prevents me from thinking that I know it all, have all the answers, and can solve any problems that come my way. Had I known that the topic would raise such a reaction, I would not have posted it. I'm hesitant to post even this above, as I'm afraid it will get a similar response, scandalizing some. I will nonetheless post it, because I think what I have said is not wholly inaccurate, and needs to be said now that the subject has been started.