"You can't explain the precession of the perihelion of Mercury" is a hit against Newton's theory of gravity.
"You can't explain "zoink", and I can't tell you what "zoink" is, nor what an explanation of "zoink" would look like" is not a hit against anything.
Also, arguments are not soldiers, and talking about "hits" and "sides" is unwise.
There have, in history, been many occasions where something was not understood. When temperature was not understood, it was still possible to explain to someone what this ill-understood "temperature" was. Specifically, it is simple to make sure that your notion of "colour" or "temperature" is similar to my notion of "colour" or "temperature" even if I don't understand what "colour" and "temperature" are.
I predict that there has never been a concept that
was not understood at some point in time
was "not easily explicable" in the sense that "the subjective experience of pain" is not easily explicable
later turned out to be well-defined and to "cut reality at its joints"
If you can come up with an example of such a concept, I will start taking arguments from vague not-easily-explicable concepts far more seriously.
On the other hand, there are at least some concepts that
were not understood at some point in time
were "not easily explicable" in the sense that "the subjective experience of pain" is not easily explicable
turned out to be completely bogus
namely, the concepts of "soul", "god", etc...
Sorry for the allegorical language if it offended you.
There is a difference between not finding a solution for a problem, and not even understanding what a solution may look like even in the abstract form.
It is also not a good sign when the problem gets to be more of a mystery the more science we discover.
The concern here is that we have an irrational view that rationalism is a universal tool. The fact that we have unsolved scientific and intellectual problems is not a proof of that. The fact that there seem to be problems that in their very nature seem to be unsolvable by reason is.
I encounter many intelligent people (not usually LWers, though) who say that despite our recent scientific advances, human consciousness remains a mystery and currently intractable to science. This is wrong. Empirically distinguishable theories of consciousness have been around for at least 15 years, and the data are beginning to favor some theories over others. For a recent example, see this August 2011 article from Lau & Rosenthal in Trends in Cognitive Sciences, one of my favorite journals. (Review articles, yay!)
Abstract: