Preamble (to pain language survey)
Pain scientists and clinicians often say that pain is a subjective experience. This is epitomized in the widespread acceptance and use of the IASP definition of pain:
Pain is “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.” (IASP Taxonomy 1979/2011)
The Note to the definition adds that “Pain is always subjective,” and goes on to state that:
“… This definition avoids tying pain to the stimulus. Activity induced in the nociceptor and nociceptive pathways by a noxious stimulus is not pain, which is always a psychological state, even though we may well appreciate that pain most often has a proximate physical cause.” (ibid.)
Even those who take issue with the IASP definition typically do not question the claim that pains are subjective experiences.
Given that toes, buttocks, guts and other body parts and organs aren’t regions of the body that can have experiences in them, the subjective experience conception of pain creates a tension with people’s routine and otherwise unremarkable practice of attributing pains to bodily parts like “I have a pain in my toe,” “my back hurts,” “I have a toothache,” etc. One might wonder whether the scientists and clinicians may be advising against the practice of locating pains in body parts. But of course, they themselves routinely engage in this practice. Are they aware of the tension? They seem not. The very same Note contains the following sentence: “[pain] is unquestionably a sensation in a part or parts of the body, but it is also always unpleasant and therefore also an emotional experience” (ibid.)
The IASP definition and the remark in the accompanying Note seem to rule out identifying pain with any objective condition of the body part to which a pain is attributed, such as any actual or potential tissue damage, injury, or any kind of physical disturbance. The implication seems to be that although a pain is typically associated with such a condition, it’s not to be identified with such. Can the pain scientists or clinicians be serious in affirming the implication that when one sincerely claims to have a pain, say, in one’s toe, one is attributing a subjective experience to one’s toe? Can they be serious in thinking that people can have subjective experiences in body parts like toes, guts, buttocks, etc.? This seems very unlikely. Subjective experiences like pains are said to be realized in the brains (or the central nervous system). Indeed, many pain scientists think of pain experiences as being in the brain. Clearly, toes, guts, buttocks and the like don’t have the complex functional organization sufficiently similar to the brain (any brain) to support subjective experiences.
So, we seem to have a puzzle. This puzzle isn’t confined only to the conception of pain had by scientists and clinicians. It seems widespread in the larger population reflecting the puzzle embedded in the folk conception of pain. To explicitly state: the puzzle stems from the fact that we seem to conceive of pains as both subjective experiences and as locatable conditions of the very objective bodily parts and organs. The folk may be excused for being sloppy, inattentive, and sometimes even confused. This wouldn’t be very surprising. The folk aren’t doing any kind of research relying on this conception after all — they are most often just trying to get by in their hectic daily lives.
But the puzzle becomes more puzzling when it’s realized that pain scientists and clinicians worked long and hard to come up with the IASP definition and the accompanying Note. Pain science is the science of pain so defined. Pain clinicians treat patients with (persistent) pain so defined. How can the pain scientists and clinicians be confused? If there is a confusion, it seems to be of such an elementary and fundamental kind that makes one wonder how the scientists and clinicians can be unaware of it. Indeed, if there is a confusion, it doesn’t seem to be even below the surface (to wit: “[pain] is unquestionably a sensation in a part or parts of the body, but it is also always unpleasant and therefore also an emotional experience” ibid). Also, if there is a confusion, wouldn’t one expect this to somehow show up somewhere — perhaps having an adverse impact on scientific research or clinical practice? But as far as anybody knows, there is no trouble or difficulty in any aspects of scientific pain research or clinical practice that is traceable to this “confusion.”
So we seem to have a puzzle of a very peculiar sort. Scientists, clinicians, and the folk alike seem to be utterly competent in attributing pains to body parts while talking of pains as subjective experiences without the slightest hesitation in their discourse or in their practical dealings with each other as well as in their clinical or research settings. Everybody seems to implicitly know what the truth-conditions of pain attributing utterances are so they routinely speak and evaluate the relevant language without any signs of confusion. Yet when asked to explicitly articulate what these truth-conditions are, most seem to draw a blank.
This puzzling situation calls for an
explanation. In particular, we need to understand how scientists and
clinicians can be operating with two apparently conflicting conceptions of pain
(bodily vs. experiential conceptions) without the slightest
discomfort or sign of confusion, especially when the apparent conflict seems so
manifest. It would be ideal to start the investigation by collecting data from
the basic pain researchers, clinicians, and health professionals themselves
about how they tend to resolve the tension between these two conceptions of
pain when the tension is brought to their attention. The results are likely to
have important consequences for our theoretical understanding of the nature of
pain and other conscious experiences.
 In the philosophical literature, this puzzle has come to be called the “paradox of pain.” We prefer “puzzle” over “paradox” since the latter may imply that the conception is internally incoherent. We don’t want to make this stronger claim. In our view, there is only an internal conceptual tension, not a formal incoherence.
 See Harold Merskey, “History and Definition of Pain,” in Chronic Pain: a Health Policy Perspective, edited by S. Rashiq, D. Schopflocher, P. Taenzer and E. Jonsson (WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, 1–10, 2008); and Murat Aydede, "Defending the IASP Definition of Pain", The Monist (Oct. 2017, Vol. 100, No. 4).
 The problem isn’t of course confined to pains but it’s about all similar bodily sensations, such as itches, tickles, pins-and-needles, etc. We routinely locate sensations in parts of our bodies and tend to treat these sensations as having an awareness-dependent existence.