Revisiting the Spectrum Argument

[Today’s guest post by Clinton Wilcox is part of our paid blogging program.]

A few years ago, Bob Seidensticker, a Patheos blogger, wrote about an argument he called the Spectrum Argument. I wrote an article in response. Seidensticker just updated a response to me a few days ago, which you can read here. I’d like to respond to the points he’s raised in his new article. To summarize his argument, there is no dividing line between “person” and “non-person”. It is a spectrum, and the embryo begins as a non-person and eventually becomes a person once it reaches a certain developmental milestone, and this milestone is the number of cells that go into making up a human person. As he says in his original article,

But the vast difference in the number of cells only begins to define the vast difference between the two ends of the spectrum. At one end, 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…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.

He makes several comparisons. A brain with only one neuron doesn’t think at all, which is a huge difference between it and the brain with one million neurons, which does think. There is a continuous spectrum from blue to green, but blue is not green. There is no objective dividing line between child and adult.

A refutation of his argument, generally

The argument can really be refuted right away. Seidensticker here completely ignores the fact of human development. Once we develop enough cells, these other structures don’t mysteriously come into existence. They develop gradually: a heart develops at around 22 days in utero, arms and legs start to form around the second month, etc. Seidensticker says “this is the spectrum we’re talking about,” but in what sense is this a spectrum? The reality is we don’t exist on a spectrum — what is human is human from the beginning. It has a human nature which directs its development and grounds its ultimate capacities, and all physical parts of the embryo eventually develop into the adult. Blue may change from green on a spectrum, but green didn’t start out as green — it starts out as blue. A human doesn’t start out as a non-human, it starts out as a human and remains human. The single-celled zygote is a fundamentally different entity than the sperm and ovum cells that went in to make it — and from then on, there is a continuity of existence from the single cell zygote all the way through that embryo’s life. The zygote doesn’t go out of existence once the cell starts to divide, it develops along the path of human development. But Seidensticker never gives us any sort of argument as to why he believes humans develop on a spectrum — he only tries to argue for it by pointing to other things that are spectrums and saying “see, they’re the same.”

Even if we consider Seidensticker’s argument as an argument of personhood, he still has to argue for why personhood is a spectrum. This would commit him to a gradualist position, similar to the likes of Wayne Sumner, who believes that sentience (i.e. the capacity to feel pain) is what grounds personhood. However, while Sumner’s argument from sentience makes sense (it is at least intuitively plausible that the reason it’s wrong to kill someone is because they can feel pain, but of course, this position is open to several counterexamples), Seidensticker’s doesn’t. Seidensticker places the value-giving property on the number of cells the entity contains because of the differences between a single-celled zygote and a one trillion celled newborn. Of course, if the pro-life position is successful, then these differences are trivial because it’s the same individual through all points in its development. After all, although I may be qualitatively different than an embryo (I’m older, I am presently rational, I can talk, etc.), I am quantitatively the same embryo that was in my mother’s womb.

A response to Seidensticker’s other points


But now let’s turn to Seidensticker’s other points. It’s trivial, but I want to start out by pointing out how amusing it is that Seidensticker claims that conservatives are trying to get votes by making an issue out of abortion, when Hillary Clinton’s campaign ran mostly on her support for abortion rights (and ultimately ended up losing the election). Donald Trump made a few comments but for the most part, his campaign was silent about the abortion issue. Was Seidensticker living in an alternate reality last year during the presidential campaign?

Cutoff line


The problem with Seidensticker’s argument here is that since we are dealing with the life of a human individual, then we must be able to make a determination. One advantage that the pro-life argument has over the abortion-choice argument is that the pro-life argument presents a clear dividing line between non-human and human: fertilization. But abortion-choice advocates generally disagree over when the dividing line is. Is it when sentience is sufficiently present, as Sumner argues? When cortical brain activity is present, as David Boonin argues? Is it when the human is sufficiently rational, as Michael Tooley argues? And even if we can decide which one of these thinkers is correct, there’s no clear dividing line at which point the developing human being attains personhood, under that conception of “person.” It does not disprove Seidensticker’s argument that he can’t come up with a clear dividing line (to argue that it does would be to risk committing the sorites fallacy), but it is a disadvantage that it has as compared to the pro-life argument.

Potential

Seidensticker responds to my arguments simply: “No, an acorn is not a tree, it is a potential tree.” “No, it is a potential brain.” Seidensticker presents no new arguments, so I can only point him to Monty Python to show why this isn’t an appropriate way to argue. The reality is that yes, the acorn is an immature oak because all of its physical parts will develop into the mature oak tree, and all capacities that mature oak will have are present in the acorn in a latent form (or it might be more accurate to say that it’s not the acorn, per se, that is the same as the mature oak tree because the acorn actually contains the oak embryo, and that oak embryo is the same individual as the mature oak tree it will become).

Simply repeating “no it isn’t” isn’t an argument, it’s contradiction.

Personhood spectrum analogy


Something similar to the acorn happens with the brain. Now, I’m not an expert on the brain or how it develops, but according to my research, a single neuron is not the brain itself, but the gray matter of the brain is made up of neurons. The neuron is only a potential brain in the sense that all the neurons will develop into the gray matter of the brain, but the gray matter and white matter must be present for the brain, itself, to actually function as a brain should.