I just realized something that probably was obvious to many people: the opposite of the pleasant isn’t the painful, but the unpleasant. Great physical effort can be painful, but it could also just be effortful and unpleasant (though there can also be a pleasure mixed with the unpleasantness). An even clearer case is distasteful food, which is unpleasant but not painful to eat.
While it would sound wimpy to talk about “the problem of the unpleasant” in place of “the problem of pain”, pain isn’t in general worse than the non-painfully unpleasant. For instance, there are distasteful foods to which I would prefer the pain of a flu shot.
It may be that among physically unpleasant events, pains monopolize the top of the unpleasantness hierarchy (test case: extreme bitterness—maybe that’s actually painful?). So while some instances of non-painful physical unpleasantness are worse than some instances of painful physical unpleasantness, some instances of physical pain are worse than any non-painful physical unpleasantness. Because of this, we worry about “the problem of pain” rather than “the problem of unpleasantness”, and we talk of grievous emotions as psychological pain rather than psychological unpleasantness. Talk of “unpleasantness” implicates we are talking about something that isn’t severe.
Even further complicating matters, it seems plausible that there are instances of physical pain that aren’t actually unpleasant. Mild soreness after exercise—that feeling of muscles well-used but not abused—might be in that category. This may even be true of some cases of psychological pain. Someone close to you has died, and you’re too numb to feel grief. Then suddenly the grief floods in, tears flow. It’s painful, but it need not be unpleasant—unlike the numbness, which was definitely unpleasant. It might even be pleasant, the pleasure of emotions functioning properly.
I know that the standard way of analyzing cases like that of exercise soreness or a flood of tears is that there is an unpleasant core but it’s outbalanced by associated pleasures. But I think that may be mistaken. The pain is there, but I am not sure that there need be any unpleasantness. What we have is something that would have been unpleasant in isolation, but in conjunction with the rest of the context we get a complex feeling that is not unpleasant. This unpleasantness is perhaps something like the red, blue and green subpixels in the white areas of your screen—the subpixels each contribute to the color (if the blue weren’t there, the area would look yellow rather than white), and in isolation they would produce their respective colors, but in the context their color is lost. Likewise, it may be better phenomenology to say that in cases like these the pain would be unpleasant in isolation, but in the context its unpleasantness is lost.
If this is right, then philosophers really should be talking about the problem of unpleasantness rather than the problem of pain, simply being careful to cancel the implicature that the unpleasantness isn’t severe.