Roman said:
Hmm, if much of our current knowledge of Norse/Germanic myths is based on the works of one author it appears that we do not really know all that much about them - there is no way one author could compile all the important myths - sounds like we are only scratching the surface of Norse mythology. I suspect this may also be the case with other old mythological systems.
Actually we have the works of several authors, despite what this thread has mentioned to date. While Snorre is important, far more important for the understanding of Norse mythology is the Poetic, or
Elder Edda, one of those anonymous collections. This was collected sometime before Snorre Sturlson started writing and (potentially late 11th through mid-12th century, but exact date uncertain), while still incomplete, has great material in it, including the Havamal and the Volsupa. Overall the Elder Edda gives us much more information about the gods and in a somewhat less tainted form.
For the Germanic we have scraps and bits, ranging from several Roman authors to the
Niebelungenlied, but all of these sources have to be taken with at least a heavy, heavy dash of salt as they were written either well after the fact or by non-practioners.
While there is a fair amount of information, some of it is repetative, much of it is incomplete, and there are huge, obvious holes in our understanding. For example, none of the goddesses take active roles in any version of the legends that we have. Also Thor, by archaeological and linguistic evidence the most popular of the gods, appears to us almost entirely in comic tales; additionally he was the patron of marriages, but there are no tales to explain his connection this way, except about his wife Sif's potentially wandering ways. On top of this we have many more tales of the Aesir gods than of the Vanir gods, yet there are almost as many shrines to the latter as to the former.
No, our vision of Germano-Norse beliefs is woefully inadequate. Anyone basing their theology on the scraps we have left would have, at best, an incredibly incomplete view of what these religions were all about in their own day. Indeed, it would be about as "accurate" as the post-Gardner vision of "witchcraft", which is held together more by wishful thinking than by any accurate information.