In Human Knowledge: It's Scope and Limitations, Bertrand Russell wrote, "A fisherman once told me that fish have neither sense nor sensation, but how he knew this, he could not tell me."
That reminds me of how abortion advocates approach the question of fetal pain.
It is, of course, a scientific question, and many unanswered questions remain. But the direction in which the evidence keeps moving is clearly that an unborn child can probably feel pain earlier than the experts previously thought.
Consider the fact that, not so long ago, it was thought that newborns could not feel pain. Surgery was carried out on newborn and premature infants with minimal or no anesthesia. But since 1986, this practice has been unacceptable, and it is recognized that they can experience severe pain.
Pain cannot be measured directly. What has to be examined, in the case of babies, are things like stress reactions, measured by the release of certain hormones in the blood, and the presence of the various anatomical structures necessary for the transmission and perception of pain.
In 1994, an article in the prestigious British medical journal, the Lancet, revealed hormonal stress reactions in the fetus. The article concluded with the recommendation that painkillers be used when surgery is done on the fetus. The authors wrote, "This applies not just to diagnostic and therapeutic procedures on the fetus, but possibly also to termination of pregnancy, especially by surgical techniques involving dismemberment." In 1991, scientific advisors to the Federal Medical Council in Germany had made a similar recommendation. And the Australian national Health and Medical Research Council requires painkillers to be used on the fetuses of animals!
In 1997, the Royal College of Obstetricians and Gynecologists reported that the fetus could not feel pain until 26 weeks, but urged anesthesia from 24 weeks. In August 2001, however, Great Britain's Medical Research Council revised that conclusion and said that pain perception may be as early as 20 weeks.
Another Parliamentary group of 15 scientists from Britain, Ireland and Australia concluded that the mechanisms for pain perception are in place and functional before the 10th week of gestation.
A lot of the uncertainty revolves around the fact that we still do not know all the physiological elements necessary for pain perception. What is becoming clearer, however, is that pain perception is not something limited to one or another area of the brain; nor is it something that suddenly "turns on" at one specific point in development. Also, the unborn may actually feel more pain than the adult because there is evidence that the mechanisms that inhibit pain seem to develop after those that enable the perception of pain.
The moral conclusion should be obvious: If in doubt, err on the side of caution.
An abortion supporter once asked me why the whole issue matters if painless killing is immoral anyway. My response was that for those who can't see that painless killing is wrong, the possibility that they are inflicting pain may be enough to pain their own conscience.