A Defense of Abortion Rights: the Spectrum Argument

Christianity and atheism debateA typical pro-life position can be stated this way: (1) human life begins at conception; (2) it is murder to take a human life; therefore (3) abortion is murder and should be considered immoral.

We’ll return to that idea shortly, but first let’s look more closely at human life. I argue that there is a spectrum of personhood during gestation.

Consider a continuous spectrum from blue to green. Where’s the dividing line? Where does blue end and green begin? We can argue about this, but we agree that blue is not green! The two ends are very different.

What age is the dividing line between child and adult? Twelve years? Eighteen? Twenty-one? It’s a spectrum, and there is no objectively correct line. Again, the line is debatable but no one doubts that a child and an adult are quite different.

An acorn is not a tree, a silkworm is not a dress, a water molecule is not a whirlpool, a piece of hay is not a haystack, and a carton of eggs is not a henhouse of chickens. Similarly, a single fertilized human egg cell is very different from a one-trillion-cell newborn baby.

Note that this is not simply about the number of cells. At one end of the personhood spectrum, we have arms and legs, fingers and fingernails, liver and pancreas, brain and nervous system, heart and circulatory system, stomach and digestive system—in fact, every body part that a healthy person has. And at the other, we have none of this. We have … a single cell. In between is a smooth progression over time, with individual components developing and maturing. That’s the spectrum we’re talking about.

Let’s approach this another way. Consider a brain with 100 billion neurons versus a single neuron. The single neuron doesn’t think 10–11 times as fast; it doesn’t think at all. The differentiation of the cells into different cell types and their interconnections in the newborn may count for even more than the enormous difference in the number of cells.

Note also that the difference between a newborn and an adult is trivial compared to the difference between the cell and the 1,000,000,000,000-cell newborn.

Some pro-life advocates argue that the humans at either end of this spectrum are identical in every meaningful way and use the term “baby” for every point along the spectrum. I’ve raised babies (with help, of course), and that makes me something of an expert in identifying babies. As an expert, I can assure you that an invisible cell isn’t a baby.

This inept attempt to collapse the spectrum by using the term “baby” for both ends is like the slogan used by the animal rights group PETA: “A rat is a pig is a dog is a boy.” In other words, there is no spectrum here: vermin are the same as livestock, which are the same as pets, which are the same as people.

No, a rat is not a boy, blue is not green, and a single cell is not a newborn baby.

A lot revolves around what we call this spectrum. Do we call it Homo sapiens? With this term, there is no spectrum, because the species is the same—the single cell is Homo sapiens, as is the newborn baby.

What about “human”? That seems a good name for the spectrum—that is, we would call the newborn human but not the cell. Or, we might call the cell human but not a human. Pro-lifers typically reject this, wanting to use “human” for both ends of the spectrum.

All right, can we all agree on “person”? I’ve heard pro-lifers reject this as well.

This game where pro-lifers deny names to the spectrum can get tiring. I really don’t care what the spectrum is called—humanity, personhood, human development, like-me-ness, whatever—call it what you want as long as the naming acknowledges the stark difference between the newborn (with arms and legs and a circulatory system and a nervous system and eyes and ears and so on) and the single fertilized human egg cell.

Now, back to the original pro-life argument: (1) human life begins at conception; (2) it is murder to take a human life; therefore (3) abortion is murder and should be considered immoral. This argument is invalid because it is oblivious to the spectrum.

Pro-lifers claim to be celebrating life, but equating a newborn baby with a single cell doesn’t celebrate life, it denigrates it.

Photo credit: Wikimedia

Other posts in this series:

“I Do Abortions Because I Am a Christian”
Don’t Like Abortion? Then Support Sex Education.
5 Recommendations to the Pro-Life Movement
Spectrum Argument for Abortion, Revisited
About Bob Seidensticker