The problem with UPG, as was pointed out at a talk I attended at the Asatru Folk Assembly’s Winternights celebration, is that it presents a false dichotomy that is actually quite harmful. This isn’t to say that the specific insights that are classified as “UPG” are in and of themselves harmful (although some could very well be classified thus), but rather that the concept itself does a disservice to the various insights that are only indirectly supported by the lore, but don’t rely on personal revelation for their provenance.
The problem with UPG as a concept is that it invites people to lump everything that isn’t contained in “the lore” into the category of UPG. For instance, take the definition found at Wikipedia:
Unverified personal gnosis (often abbreviated UPG) is the phenomenological concept that an individual’s spiritual insights (or gnosis) may be valid for them without being generalizable to the experience of others. It is primarily a neologism used in polytheistic reconstructionism, to differentiate it from ancient sources of spiritual practices.
The lore isn’t necessarily restricted to ancient written sources (although they do form a part of it). Numismatics, philology, historicity (which is a field of study quite different from history), etc. can all legitimately be found under the umbrella of “the lore”. But insights of modern scholarship (professional or amateur), should they not be based upon a concrete quote from some ancient writer, are all too often lumped together with the “insights” that someone received directly from Zeus in a dream. Therein lies the problem.
To take one example; say I have an insight concerning the timing of rituals that is derived from reading some sources in Christian penitential books. They happen to mention “making offerings to demons on Thursdays” and I put that together with other information I have, such as the etymology of “Thursday”, Christian practices that were forbidden on Thursdays, and many other bits of evidence. From all that information, I conclude that Thursdays are probably the best day to make offerings to the local land-spirits.
However, because there’s nothing in “the lore” that explicitly states that Thursday is the best day to make such offerings, my insight is relegated to the same shelf as someone who says that Pan came to her in a vision and told her that he likes twinkies. The same can be said of insights such as Dumezil’s trifunctional hypothesis, Margaret Murray’s theory of a witch-cult survival, or Ronald Hutton’s conclusions about the nature of Pagan religion in southern England. Whether or not you agree or disagree with them, they are necessarily of a different nature than an insight brought to someone who has a dream or vision of a God or fairy. But the concept of “UPG” makes no such distinction.
It’s a subtle point, but I think it’s a vital one. “UPG” is not a helpful categorization because it has led to a differentiation between “the lore” and everything else. As Pagans and Heathens, we need to come to the understanding that there are gradations of historicity, and that to lump everything that doesn’t come explicitly out of a written source in the same category does an enormous disservice to scholarship in general. This is not to say that all direct revelations from the Gods or spirits have no value; just that they shouldn’t necessarily be treated on the same level as everything that is not in “the lore”.