Wicca

Alright, someone who has more direct experience with this belief system or people that participate in it, I'd like you to explain its basic tenants to me because, honestly, I'm running into brick walls of rationality.

I don't like to shout "bullshit" on anyone's beliefs, to each their own I say, but I do think people need to have at least some kind of reasonable framework upon which they are based.  That in mind, I keep hitting snags in what I know of Wicca.

So as I understand it, the basic sort of deal for Wiccans is that they are trying to recreate pre-Christian systems of worship and activities, particularly those of so-called "Celtic" origins.  Additionally, it is the case that these aren't even necessarily sincere belief in the existence of polytheistic gods, the like of a Celtic Zues or Athene, but merely the use of said deities as embodiments of ideals and values, as in the case of the Asatru who look at Norse gods as symbols of what they aspire to be, not as gods that literally control the storms and the seas.

Here's where I stop understanding... most pre-Christian religious practices, in particular those of Europe and the British Isles, were primarily oral in nature, which is to say that none were written down.  What little evidence we have is often cited from foreigners, often Romans and Christians, documenting what they observed in local populations as they were often wont to do.  This may be seen as the case of Beowulf and many of the norse eddas and sagas.  In the case of most Celtic practices, however, fierce Roman resistance to its practice effectively annihilated it in the known European world.  We really do not know what these ancient peoples practiced: the people who did were destroyed and little of it was written down by their conquerors.

So I cannot help but wonder: from whence do Wiccans claim their systems of beliefs?  Did a massive archaological find of previously unknown proportion escape my notice and change our entire understanding of history?

And what of this constant reference to "Witchcraft" and the use of spells?  I believe that the first true, widely spread document of witchcraft was the Witch's Hammer, the Malleus Maleficarum, which was written, I'm pretty sure, around the 14th or 15th centuries (I may be mistaken here, in which case please correct).

I just don't get it... But I am serious in my desire to see from whence these people come.  So those learned out there, please aid a bored scholar typing on teh internets at ungodly hours of the morning to people he doesn't know about questions most don't particularly care about.  But hey, it's an off-topic forum right?

Maybe there isn't anything to get?