It is 'arrant nonsense'

says William Safire in Arrant Nonsense:
"If you Google errant, you get nearly three million citations, their sense "roving, straying, sometimes from high standards"; arrant gets only one-tenth as many. But if you enter the phrase "arrant nonsense," you get 35,000 to a mere 772 for "errant nonsense." People know the word with the a means "utter, thoroughgoing, complete," usually carrying the connotation of disapproval. Arrant, the former variant, is now out on its own, its meaning independent of the wandering errant. Let the dictionaries catch up with the living language."
The link from a comment in the very interesting post The Nature of Modern Finance:
"Is modern finance more like electricity or junk food? This is, of course, the big question of the day.
.........
Given what we’ve seen over the past 12 months, which way should we lean: towards believing in the positive power of finance, until the opposite is proven; or towards being skeptical of finance in its modern form, until we see evidence that this actually makes sense?

Surely out skepticism should extend to financial innovation. Show me the evidence that this kind of innovation really adds value, socially speaking – rather than providing a very modern way to extract amazing “rents”."

The comment which drew the response is from "Old Lady in Red":
"To summarize the common understanding of the principle, “Of several acceptable explanations for a phenomenon, the explanation containing just the facts will do.”

What is happening today in finance is errant nonsense, fantastical craziness, bizarre lunacy and, fifty years from now, we will not be able to fathom how we could have been so stupid for so long."