pain as subjective experience

That pain is a subjective experience seems to be a truism. Given our common-sense understanding of pain, this seems to be the more dominant thread: instead of treating pains as objects of perceptual experience, it treats them as experiences themselves. Indeed it is this thread that the official scientific definition of ‘pain’ picks up and emphasizes, which was first formulated in the 1980s by a committee organized by the International Association for the Study of Pain (IASP), and has been, since then, widely accepted by the scientific community:^[1]

Pain: An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.

Note: Pain is always subjective. Each individual learns the application of the word through experiences related to injury in early life… Experiences which resemble pain, e.g., pricking, but are not unpleasant, should not be called pain. Unpleasant abnormal experiences (dysaesthesia) may also be pain but are not necessarily so because, subjectively, they may not have the usual sensory qualities of pain. Many people report pain in the absence of tissue damage or any likely pathological cause; usually this happens for psychological reasons. There is no way to distinguish their experience from that due to tissue damage if we take the subjective report. If they regard their experience as pain and if they report it in the same ways as pain caused by tissue damage, it should be accepted as pain. 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. (IASP 1986, p. 250); Cf. (IASP-Task-Force-On-Taxonomy 1994)

Like other experiences as conscious episodes, pains are thought to be private, subjective, self-intimating, and the source of incorrigible knowledge. These elements can certainly be found in the IASP characterization, which also adds that pain experiences are unpleasant. Indeed, by emphasizing that pain is always a “psychological state” the note warns against a conception of pain suggested by the first thread above.

Interestingly, however, when we talk about pains as experiences, we also, in the same breath, talk about feeling them as if these experiences were also the object of some sort of inner perception, which suggests introspection. Indeed the discussion of privacy, subjectivity, self-intimation, and incorrigibility naturally forces us to talk this way.

Pains are said to be private to their owners in the strong sense that no one else can epistemically access one’s pain in the way one has access to one’s own pain, namely by feeling it and coming to know one is feeling it on that basis. This sharply contrasts with the public nature of objects of standard perception, i.e., perception of one’s immediate extramental environment including one’s body. Let’s call this exteroception, to contrast with introspection which is access to one’s intra-mental activity. So, for instance, the very same apple I see on the table can be seen by others in possibly the exact way I see it, so is not private in this sense.

Pains also seem to be subjective in the sense that their existence depends on feeling them. There is an air of paradox when someone talks about unfelt pains. One is naturally tempted to say that if a pain is not being felt by its owner then it does not exist. Again compare the subjectivity of pains to the objectivity of the objects of standard exteroception. The apple I see does not depend on my perceiving it in order to exist: (pace Berkeley and phenomenalists) its existence is independent of my, or for that matter anyone else’s, seeing it.

Not only people seem to have a special epistemic access to their pains, they seem to have a very special epistemic authority with respect to their pain: they seem to be incorrigible, or even infallible, about their pains and pain reports: necessarily, if I sincerely believe that I am in pain, then I am in pain. Conversely, if I feel pain, then I know that I am in pain. Again this conditional seems necessarily true. This is the self-intimating aspect of pain experiences.

In short, there doesn’t seem to be any room for a possible gap between the appearance of pain and being in pain (i.e., no appearance/reality distinction applicable to pain). As Kripke famously put it:

To be in the same epistemic situation that would obtain if one had a pain is to have a pain; to be in the same epistemic situation that would obtain in the absence of pain is not to have a pain…. Pain … is not picked out by one of its accidental properties; rather it is picked out by its immediate phenomenological quality…. If any phenomenon is picked out in exactly the same way that we pick out pain, then that phenomenon is pain. (Kripke 1980, pp. 152-53)

If there is no appearance/reality distinction applicable to pain, then it seems that one cannot be mistaken about one’s beliefs about one’s pain formed on the basis of feeling pain in the way one can be mistaken about the existence and properties of the apple one sees. In the latter case, appearances can be misleading precisely because the perceptual appearance of an apple might not correspond to what the apple is like in reality. In apparent contrast to pain, normal exteroception always involves the possibility of misperception, and thus miscategorization (i.e., misapplication of concepts to the objects of exteroception).