Tolkien is quite insistent on maintaining that his world of Middle Earth is not an imaginary world, but rather that his tale is on of this Earth, but the time period in which he crafts this tale is imaginary (Letters, 183). This concept can be a bit difficult to grasp-the lands and names and events bear no resemblance to the world we currently inhabit at first look. As was said in class, if the Shire is supposed to be located where Oxford currently resides in England, and if Mordor is somewhere off in Eastern Europe, the whole thing doesn't make any sense-one does not simply walk over the English Channel to Mordor. Of course, such a perspective is too literal, and not very fun, but it still shows why it's difficult to grasp the connection between the two worlds being one. The fact that we obviously have no history of great battles of elves and orcs and hobbits and men in the great plains of Eurasia also make it a somewhat difficult task to grasp that this Earth is our Earth. Comparing it to King Arthur makes it a lot more understandable.
The myth of King Arthur is known to almost all, and has been endlessly replicated in stories and tales ranging from the silly (Monty Python and the Holy Grail) to the science fantasy (A Connecticut Yankee in King Arthur's Court). Most people (I hope) understand that his tales are the work of fantasy, but there may be a small grain of truth to some of the legend. Whether or not this is true is up for debate, but his tales come from a time where it is impossible to disentangle the mythical and the historic. If we are to discard the tales because they are just myths, we risk losing what could be some valuable insight about an era in English history. On the other hand, we can't take these myths at face value-we know that Merlin did not construct Stonehenge with wizardry magic, but we also don't know what else is purely myth. The time of Arthur is one that is imaginary-but they take place in an England that is very real.
To apply this to Tolkien, we can start to get a clearer picture of what he was attempting to do. We can see now that this era in Earth's history never happened, but it did happen on Earth. It is a time between times-like finding a whole number between 3 and 4. It doesn't exist, but yet it does exist in a certain place and period. What Tolkien is doing is taking the traditional idea of moving back in time to an era where myth and history intertwine-and then keeping on moving back. The facts begin to fade away and leave just the myth-and Tolkien takes this myth, and adds onto it. He is building a new history from the basis of myth, but still placing it in the same world, but one of a completely imaginary time. It really should not be held up to the same light as our own timeline.
To say that the tales of Tolkien take place in a "lost" time is a harder preposition to state. Time has a fairly logical progression. Event A happens, Event B happens, Event C happens, so on and so forth. To say that this was a time that was lost to the ages and recorded history is a little crazy-it's hard to lose 8000 years of human history. Or to say that there would be no trace of any of the impact of this history left on this Earth. Tolkien runs into some trouble when he starts to make this claim-that it is a "lost" epoch, rather than one that never happened at all. For terms of pure fantasy, this is fine, but he put so much work and effort into trying to stress that the world was real, but the events and people and times were not-and yet they are still our world. And it weakens the point he is trying to make. He is trying to create a history of pure myth, and trying to latch it onto real history at some point is a dangerous thing. In fact, it's better to claim that the world of Middle-Earth is our Earth, but not the Earth we live in. The planet is the same. The universe is not. There are parallels, yes. But to bring the myths of Earth-with Numenor standing in as the mythical cataclysm of Atlantis and so on-is dangerous. Like Arthur, Atlantis has an imaginary time, but this time does exist within our chronology (to an extent), whereas Middle Earth should exist outside our chronology. There is no reason why the myths of our world cannot be a part of the myths of Tolkien's Middle Earth-but it is hard to hold your grip on reality when a myth happens twice.
The imaginary time of Tolkien is at time where our myths are real. But to try attaching this history of myth to our history of...well, history, you once again blend myth and reality, and you cannot know what is real-but one history is real, and one is imaginary. Sometimes reading his works, it's hard to tell if he ever made that difference. A time on our world outside time, yet still connected to our world (Tolkien), versus a world just like our world, with it's own myths and histories, but one outside of separate (a parallel world). I don't know, it makes me feel saner imagining a parallel world just like ours-even a world people like Tolkien can reach, versus imagining a time that is both real and not real at the same time. Hopefully that made sense.