Conjoined Twins: A Response and a Question [Serge]

Daniel states in the comments:

While it's true my biological formulations may be undersophisticated, I nevertheless feel like you have failed to address my primary question, so let me see if I can 'tweak' the conjoined twins scenario to better bring out my question.

I believe I did, but I'm happy to clarify.

As you probably know, fetal development can really go wrong. While some conjoined twins are conjoined at the hips, or the liver, or whatever, others are almost entirely fused (e.g. up to their upper-torso). I'll have this be case A.

Agreed. There are sometimes two human organisms that have their bodies fused together.

You probably also know that in some cases, one of the twins can be underdevelopped--to the point of lacking a heart, a brain, or simply being underweight. In some cases, a baby can be born with odd extra limbs (e.g. a leg sticking out of the side, or teeth in the back of the neck), even though the second 'twin' has been subsumed back into the first (or never really developed in the first place). Let's have this be case B.

OK. You are speaking of the (horribly titled) parasitic twin or rare inclusion twin. I need some more information to address this, but you state that the dependent twin "never really developed in the first place". Let's go on.

Since you seem to be more up-to-date on your biology than me, make whatever modifications to the two above scenarios for them to be medically plausible.

So far, so good.

In case A, I affirm that it is morally wrong to cut off the second twin's head. This is murder.

Agreed. It is wrong to cut off the head in case A because that action would result in the death of a human organism. The same would apply if you poisoned the twin. Performing an action that results in the death of a human being without justification would be morally wrong.

In case B, I affirm that it is morally acceptable to cut off the second twin's limbs (the leg sticking out of the first twin's torso).

Generally you are correct if the second "twin" is not a human organism. If the "twin" is unable to guide its own development and to integrate its bodily functions as a biological organism, then there is no moral qualms about its removal even though it is made up of human cells. Human organisms and teratomas begin as a single totipotent cell. However, there are distinct differences which maked the former a human organism and the latter not. Robert George mentions one:

If the embryo were not a complete organism, then what could it be? Unlike the spermatozoa and the oocytes, it is not a part of the mother or of the father. Nor is it a disordered growth such as a hydatidiform mole or teratoma. (Such entities lack the internal resources to actively develop themselves to the next more mature stage of the life of a human being.)

The former develops and integrates its own bodily systems, the latter does not. It is immoral to kill the former and not immoral to remove (and kill the individual cells of) the latter. This is true whether they are fused together or not.

Now, what accounts for this difference in ethical decision making? Both case A and case B are fused human organisms (two or one depending on how you look at it).

I think I covered this, but you are wrong here. Case A involves two human organisms fused together. Case B involves one human organism. Just like a human being with a teratoma that is removed, the fact that the extra part was once a totipotent cell makes no moral difference. If there was another human organism fused in case B, it would be immoral to kill it.

If killing a human organism is always wrong (which is what I understand you and Scott to be saying), then chopping off limbs in case B is murder.

Nope. Chopping off limbs in case B would be immoral if and only if it resulted in the death of a human organism. It does not. My logic is consistent.

To me, this is counterintuitive. Which is why I'll stick with my view: destroying a functional brain is murder, because the brain is the seat of the soul (they go hand in hand).

I hope I answered your questions, for I have one of my own. My example is a realistic one that could happen. Lets say there are two xiphopagus conjoined twins that are born. This means they are joined by the xiphoid cartilage in the ribcage and thus can be easily and safely separated surgically. However, as the twins are being delivered, one of them suffers head trauma and is born comatose. We have no way to determine when , if ever, the one twin will come out the coma, and what lasting effect the coma will have on his future development.

Question: should we perform a separation procedure on the twins or simply kill the one in the coma?

Using my analysis, it would be wrong to kill the comatose twin because he is a living human organism, albeit one who has suffered an injury. However, under your view, I don't see why it would be wrong to kill the other twin off. It has never experienced consciousness, and does have a "functional brain" (using your terminology). It seems to lack the working neural structures that would otherwise enable it to have moral value in your view.

What do you think? Thanks again for the interaction.