The assumption here is that human life is valuable solely because of a biological process that occurs at conception. At conception, the reasoning goes, something happens that makes the previously non-valuable sperm and egg into an entity as valuable as that of any other living person. Moreover, this reasoning indicates that nothing else other than the genetic changes that occur at conception make human life valuable; after all, if the zygote is as valuable as you or me, nothing we have that the zygote doesn’t could contribute to our value.
The question of what makes human life inherently valuable is, of course, a difficult and complex one, and there is reasonable debate about what qualities those might be. But both pro-life advocates and pro-choice advocates agree that “human life” is not inherently valuable on its own. After all, we don’t say that the living cells in an appendix that has been removed are valuable human lives, and it is no tragedy when a dermatologist removes a lipoma from a patient’s arm. These are all just clumps of human cells.
But as pro-life advocates are quick to point out, we ourselves are also “clumps of human cells”. What is it about our nature that makes our lives valuable but not that of the lipoma or appendix, also a “clump of human cells”?
We might think of some valuable aspects of ourselves that we have that the lipoma doesn’t have. We have thoughts. We have desires – to live, to act, to be heard. We have relationships with other people and animals. We have emotions. All of these aspects of ourselves serve to make our lives more valuable than that of the lipoma cells. We have, in short, mental states that make our lives inherently valuable and meaningful.
Are these mental states the key to our value as people? They are certainly a much better criteria than the mere presence of human DNA. Imagine that someone you knew did a DNA test and found out that she didn’t have human DNA – she was a mutant, say, or an android. Would her life suddenly cease to have meaning or value? I would hope all of us would agree that, regardless of her DNA type or lack thereof, she would still have the same value as she did before we knew she wasn’t technically “human”. And we could repeat this thought experiment with any other specific aspect of biology. Intuitively, we understand that it’s our thoughts, experiences, and other mental states that make our lives valuable, and make it wrong to kill us.
Can we apply these intuitions to our understandings of abortion? Scientifically, we know that our brain can’t produce thoughts or desires without a cerebral cortex, which develops in the fetus towards the end of the third trimester and continues to develop during the first months of life. Of course, the presence of an organ that can create mental states does not mean that the mental states necessarily exist. Research on the biology around childbirth concludes that the womb anesthetizes the fetus, and that the baby’s first conscious experiences begin with the wave of norepinephrine that is released at childbirth. Regarding the research around fetal development and infantile consciousness, we can conclude that a woman giving birth really does bring a person into the world.
Pro-life campaigners often respond to this argument by claiming that it devalues the life of infants (“there’s no difference between a 9 month old fetus and a newborn baby!”) but we can show how it is consistent to view the lives of infants as inherently valuable while acknowledging that abortion is not a harm even in the case of late pregnancy terminations.