The question of whether abortions should be legal has nothing to do with science. The pro-choice and pro-life movements alike make a strategic mistake every time they try to justify their position by rooting it in the science of life, consciousness, “identity” or the nervous system.
What science can tell us
There are some things that science can tell us about the ontogenesis of human organisms. For example, we know that a fertilised egg cannot think or feel pain because it has no brain or nerves. We also know that a fertilised egg is alive in the same sense that your skin cells are alive and the fungus growing on your toes is alive. We also know that a fertilised egg is not “viable”, meaning that it cannot survive if removed from the womb.
An individual sperm cell and an unfertilised egg are also alive in the same sense that your skin cells and the fungus growing on your toes is alive. Any individual cell, as long as it is located in the correct cellular environment, will sustain itself through a complex system of self-producing and self-maintaining chemical reactions. That is no less true of a blood cell than an ovum. Being “alive” is a pretty low bar to reach.
Science can also tell us that around week 8, a foetus can react to touch. This doesn’t tell us much about its “experience” or “consciousness”, however, because amoeba and ants, and even some plants, also react to touch. You can scream moral outrage at the comparison, but the fact remains: if the only criterion that you are looking at is the question “does it react to touch?” then an 8 week foetus and a Venus flytrap both pass that test.
The notion of “being able to survive outside the womb” is a pretty grey area
After 25 weeks, in the third trimester, a foetus can respond to sound, and can respond to painful stimuli by recoiling. By itself, this still doesn’t tell us much, since plants also respond to sound and jellyfish respond to painful stimuli by recoiling. We still don’t know what the “experience” of the foetus is like, any more than we know what the experience of a jellyfish is like.
At some point, the infant is capable of surviving outside of the womb. This seems pretty clear-cut, right? However, some infants must be transferred to special medical care units immediately after birth. Different infants need different levels of “womb-like environment” for a period of time before they can be taken home from the hospital.
From a purely scientific perspective, the notion of “being able to survive outside the womb” is a pretty grey area. It is likely to become even more grey as our technology advances.
For that matter, all human infants need extreme levels of care for the first several years after birth. No human infant can survive “on its own”, per se, for a very long time. Tiny post-birth humans need to be coddled and fed and washed on a regular basis. If we looked at the question “When is it able to survive on its own?” most humans don’t pass that test until several years after birth. Some never get there at all.
That may sound a bit snarky, but there is an important point to be made: from a purely scientific standpoint, none of these distinctions is hard-and-fast, and none of them provides a clear-cut or obvious delineation of when we should start calling this organism a human being with political or moral rights. We certainly have strong feelings and intuitions that the unfertilised egg should not be called a “person” and the post-birth human should; however, even those cut-off points are more practical than they are scientific.
What science cannot tell us
Science cannot tell us when “consciousness” begins. So far, this still remains the philosopher’s bailiwick. According to some philosophers, consciousness exists in all life, including trees, flowers and the lowly amoeba. After all, these things all respond to stimuli. They all engage in the continual chemical processes required to build and maintain themselves as individual entities, existing separate from the world around them. Many would argue that they must, therefore, have some form of “consciousness”, even if it is only a very primitive one. Others, of course, set the bar higher.
If you consider gender to be a core element of “personhood”, then conception is not when personhood happens
Science also cannot tell us everything there is to know, biologically, about what kind of person will emerge from the moment the egg is fertilised. Contrary to common belief, a fertilised egg doesn’t even have a specified gender yet. One in 60,000 women have one X and one Y chromosome, and yet they are still very much women.
In fact, the ratio of women who have an X and a Y chromosome is much higher among actresses and fashion models than in the general population. If you are a heterosexual man, there’s a good chance you’ve lusted after a woman with an X and a Y chromosome at one point or another. But don’t worry: even though it was not predicted by her DNA, she was still very much a woman.
This is important because the notion that all of the basic, fundamental biological characteristics of a person are defined at conception is simply wrong. If you consider gender to be a core element of “personhood”, then conception is not when personhood happens.
The wrong argument
The reason science cannot be used to give an “objective” answer to the abortion question is that there is no “objective” answer. This is a matter of deeply personal feelings, and it should be argued and presented as such.
Nobody on either side of the debate will ever convince the other side to change their mind by articulating a position on “when the technical definition of the beginning of life is”. People don’t assassinate doctors and throw bags of blood at the walls of a building because of what they think the “technical definition of life” is. It is the wrong argument to have.
In today’s world, with today’s technology, it is increasingly important to have clarity on this issue. Unlike 100 years ago, the question of abortion is tied up with questions about “trait selection”, cloning, and stem-cell research.
But despite what seems like an environment of continual debate, it does not appear that anybody is changing anyone else’s mind. At least part of the reason for this is the misuse of the rhetoric of science.
This is a complex issue, with strong passions on both sides
Liberals get their feet tangled up when they want to pin the justification for pro-choice rights on some kind of technical definition of what is and is not a “person”. This argument eliminates the possibility of differentiating between different motivations for abortions. After all, if your stance is that abortion is OK because a human foetus is technically nothing more than a clump of cells, then it should be fine to have an abortion if you find out that the foetus may turn out to be a girl. Or of below-average intelligence. Or short.
Conservatives, on the other hand, get themselves ensnared when they want to pin the justification for pro-life rights on some kind of technical definition of “feeling pain” or “personhood” because, as we already went over, these are not scientifically definable terms. Instead, we have court cases where scientists paid by different interest groups drone endlessly on and on with “suggestive” evidence that can be interpreted in too many ways to count.
The dialogue must move past that. The abortion debate will continue, of course, and it rightfully should. This is a complex issue, with strong passions on both sides. Our culture is going through the natural and democratic process of “figuring out where we stand” on the issue. But that conversation is only hurt, not helped, any time “science” is invoked in a moral or emotional debate.