Online research in philosophy

How can a pain wake you up? You were not dreaming, nor did any bodily stimuli filter into your consciousness. You did not just wake up and realize you were in pain, as you might wake up and realize it is Saturday. You were deeply, dreamlessly asleep, and suddenly you were awake, and in pain. How is this possible? If pain exists only inasmuch as it is experienced, it seems that the pain did not exist when you were asleep, and so could not have woken you up. I shall argue that you were woken by a pain sensation that you did not know you had, so that the distinction between what is and what is known holds even for the contents of consciousness. This illuminates the relationship between consciousness and attention, and casts light on the Classical Empiricist tradition that identifies the foundations of knowledge with direct experience.

Functionalism cannot accommodate the possibility of mad pain—pain whose causes and effects diverge from those of the pain causal role. This is because what it is to be in pain according to functionalism is simply to be in a state that occupies the pain role. And the identity theory cannot accommodate the possibility of Martian pain—pain whose physical realization is foot-cavity inflation rather than C-fibre activation (or whatever physiological state occupies the pain-role in normal humans). After all, what it is to be in pain according to the identity theory is to be in whatever state that occupies the pain role for us.

A functional interpretation of facial expressions of pain is welcome. Facial expressions of pain may be useful not only for communication, such as inviting help. They may also be of direct use, as parts of writhing pain behavior patterns, serving to get rid of pain stimuli and/or to suppress pain sensations by something akin to hyperstimulation analgesia.

The aim of this paper is to show that the empirical and conceptual constraints arising from the scientific research on pain phenomena should be taken into account in philosophical discussions concerning the nature and function of pain; otherwise, there is a good chance that philosophers will advocate too simplistic, confused or even outrightly mistaken theories or conceptions of pain. In order to prove this point, one of the most influential philosophical theories of pain—the so-called perceptual view of pain—is put to scrutiny in the light of the psychological, clinical and neurophysiological data coming from the field of pain research. More specifically, these data are presented in such a way as to show that the sensory quality or sensory aspect of pain is, contrary to the objectivistic claims of the perceptual view of pain, a necessary component of our total pain experience.

Do animals other than humans feel pain? How do we know? Well, how do we know if anyone, human or nonhuman, feels pain? We know that we ourselves can feel pain. We know this from the direct experience of pain that we have when, for instance, somebody presses a lighted cigarette against the back of our hand. But how do we know that anyone else feels pain? We cannot directly experience anyone else's pain, whether that "anyone" is our best friend or a stray dog. Pain is a state of consciousness, a "mental event", and as such it can never be observed. Behavior like writhing, screaming, or drawing one's hand away from the lighted cigarette is not pain itself; nor are the recordings a neurologist might make of activity within the brain observations of pain itself. Pain is something that we feel, and we can only infer that others are feeling it from various external indications.

Dennett has maintained that a careful examination of our intuitive notion of qualia reveals that it is a confused notion, that it is advisable to accept that experience does not have the properties designated by it and that it is best to eliminate it. Because most scientists share this notion of qualia, the major line of attack of his project becomes that of raising objections against the ability of science to answer some basic questions about qualia. I try to show that science appeals to qualia and that it in fact adheres to a notion of qualia different from the one that Dennett has attributed to it. It is argued that qualia are amenable to scientific investigation and that this is the reason why science contributes toward the clarification of the notion of qualia. I also try to show that Dennett's skepticism about the abilities of science in answering questions posited by one of his thought experiments is unwarranted. I conclude that we need not accept Dennett's eliminativism about qualia.

What follows raises objections to some arguments that claimthat a principle of applicability of ordinary pain talkconstrains developments in the pain sciences. A more apt pictureof lay use of pain language shows its non-theoretic character.Since instrumentalism and eliminativism are philosophical viewsabout the status of theories of pain, neither is a threatto clinical use of standard pain lingo. Perfected pain theoryis likely to enhance and improve pain language in clinicalsettings, should such theory find its way into popular ideasand talk of pain.

This paper discusses recent neuroscientific research that indicates a solution for what we label the ''causal problem'' of pain qualia, the problem of how the brain generates pain qualia. In particular, the data suggest that pain qualia naturally supervene on activity in a specific brain region: the anterior cingulate cortex (ACC). The first section of this paper discusses several philosophical concerns regarding the nature of pain qualia. The second section overviews the current state of knowledge regarding the neuroanatomy and physiology of pain processing. The third section highlights the recent research by Rainville et al. [(1997) Pain affect encoded in human anterior cingulate but not somatosensory cortex, Science, 277, 968-971], which suggests that pain affect is encoded in the ACC. The final section of the paper spells out exactly how these data affect the causal problem of pain qualia.