Online research in philosophy

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.

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.

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.

Identity theorists make claims like ‘pain = C-fibre stimulation’. These claims must be necessary if true, given that terms like ‘pain’ and ‘C-fibre stimulation’ are rigid. Yet there is no doubt that such claims appear contingent. It certainly seems that there could have been C-fibre stimulation without pains or vice versa. So identity theorists owe us an explanation of why such claims should appear contingent if they are in fact necessary.