On my last trip to the library to pick up some stuff on hold*, I ran across a couple of books which I remembered being blurbed about at the time of their release as being written in the style of this or that type of book from decades past (e.g., The Qincunx).
I've flirted with the idea of writing books like that — something clearly modeled in the manner and spirit of a work of previous days, although of course written in the present day. The problem, as I've come to understand it, is that it is literally impossible to write such a thing.
Everything we write is always written in the context of the present. Even if we try to write something that hearkens back to a previous historical frame of reference, we're still doing that in the present. That inevitably colors our approach and our outlook; that makes it far harder to, for instance, write something that would be unforgivably sexist or racist today but would be "appropriate for the period" — in big part because we know a present-day audience is the one reading it.
I'm not convinced this is something to wring our hands about, either. It means we have all the more incentive to pay attention to how we look at both the past and the present. We shouldn't shy away from writing historical fiction. We should just not be obsessed with trying to reproduce something that doesn't exist anymore, in big part because the people who both created it and received it don't exist anymore either.
Barrows Dunham in Man Against Myth talked about how each change in society brings about a new kind of man. "The primitive warrior has long disappeared, and neither imitation nor cynical jest can reconstitute him in modern society. The patriarch, the Greek gentleman, the Roman noble, are gone. The medieval knight lies buried with his battle-ax. With each have disappeared — and somewhat to the world's relief — not simply bone and sinew, but a whole way of acting."
In the same way, we shouldn't shed tears over the fact that Anthony Trollope was a product of his moment in time and the grace of his readers, or that to write a novel in precisely his mode would not invite much more than a raised eyebrow. What Trollope did in his time, we can still do in ours — but we have to do it in the way that matters most to ours right here and now. We cannot bring Trollope or any of his contemporaries back to life as-is; we have to reinvent them anew.
* Among the goodies in waiting was Insurmountable Simplicities, a book which looks very much in the vein of Raymond Smullyan's brilliant logic-twister tomes such as What Is The Name Of This Book?, which I really have to get around to writing about one of these days.