The 100 recently wrapped up its second season. The show is based on a book of the same name, but only loosely follows it. The show is set about a century after a nuclear war occurred on Earth. There are three major types of survivors: those who lived on space stations (Sky People), those who remained on the ground (Grounders), and those who took over a military installation at Mount Weather and have lived inside the mountain (Mountain Men). The Grounders are adapted to the higher radiation levels, and so are the Sky People due to exposure to radiation in space. The Mountain People, however, are not adapted and will die almost instantly upon exposure to the outside world. The show mainly focuses on the Sky People, beginning with their struggles in space which force them to return to the surface and continuing with their interactions with the other two types of survivors that they find there.

The finale, “Blood Must Have Blood, Part 2,” contained an interesting moral dilemma. The Mountain People are led by Cage, a tyrant who is willing to use any means necessary to make his people capable of living on the surface. He has captured about 40 Sky People and his underlings are forcibly extracting their bone marrow for transplants into his people so that they can have resistance to the radiation. Cage intends to exterminate the captives in the process. Clarke, the leader of a small strike force of Sky People, only has one way to stop him: reverse the air filtration of Mount Weather to flood it with radiation, thereby killing all of the Mountain People, including hundreds of innocent civilians who are not involved with or even supportive of Cage’s actions. She struggles with this decision, but ultimately chooses to flip the switch and kill the Mountain People to save her people. From a libertarian perspective, was Clarke’s decision justified? Let us see.

Essentially, this is a more complicated version of the problem of innocent shields. The Mountain People other than Cage and his underlings are innocents, but so are the captured Sky People. Clarke effectively kills the aggressors (except for Cage, who has already made himself resistant to radiation but is killed by a Grounder shortly after escaping Mount Weather) but wipes out the innocent Mountain People to save the captured Sky People. Unquestionably, Clarke was justified in killing Cage’s underlings and trying to kill Cage. They were committing acts of murder and were therefore estopped from complaining about violations of their own rights to life. But what of the innocents among the Mountain People? To answer this, we need to consider two libertarian theories on the matter of innocent shields: that of strict non-aggression and that of negative homesteading.

Strict adherence to the non-aggression principle would suggest that the Mountain People civilians are non-aggressors and that harming them is immoral. But if this is true, then the captured Sky People are doomed. If Clarke cannot kill the Mountain People, then Cage and his underlings will murder the captured Sky People. But the non-aggression principle is not an axiom; it is a logical corollary of the right to exclusive control over one’s physical body, which is the starting point for any logically rigorous moral theory. (To argue against this right would result in a performative contradiction.) To have another theory for this situation, we need to find another such logical corollary of bodily ownership and use it. Toward that end, Walter Block introduced the concept of negative homesteading. To quote Block,

“In ordinary homesteading, or what we must now call positive homesteading to distinguish it from this newly introduced variety, it is the first person upon the scene who mixes his labor with the land or natural resource who comes away with the property rights in question. It is the first man who farms a plot of land, who becomes the rightful owner. A similar procedure applies to negative homesteading, only here what gets to be “owned” is a negative, not a positive. This concept refers to some sort of unhappiness, not a benefit such as owning land. The ownership of misery, as it were, must stay with its first victim, according to this principle. He cannot legitimately pass it onto anyone else without the latter’s permission.”

At first glance, the case at hand appears to be more complicated than the case Block discusses first:

“A grabs B to use as a shield; A forces B to stand in front of him, and compels him to walk wherever A wishes. A then hunts C in order to murder the latter by shooting him. C also has a gun. Is it legally permissible for C to shoot at A in self defense under libertarian law?”

Here, there are groups rather than individuals, and A is using B as a shield while killing C that is not armed. D must decide to either kill both A and B or to allow A to kill C. Replacing D with C is functionally equivalent because D (Clarke) is acting as C’s (Sky People’s) agent, and the moral limitations of one’s own actions are identical to the moral limitations of the actions of one’s agent. As groups have no existence apart from the individuals which comprise said groups, this difference may also be discarded. As such, we are back to the original case: C must choose either to allow oneself to be murdered or to kill both the aggressor (A) and the shield (B).

To use the theory of negative homesteading, we must identify the first homesteader of the misery. This is the Mountain People. Cage started this scenario by assuming a leadership position over the Mountain People, to which they did not object even though they were numerous enough to overthrow him. It is impermissible for the Mountain People to transfer this misery to the Sky People. Even in the best case for Cage and his underlings, which is that they would let the Mountain People go free after giving them the Sky People’s bone marrow, the Mountain People will have succeeded in passing off enough misery onto the Sky People to kill them. Thus, the theory of negative homesteading permits Clarke to do what she did even though a strict view of the non-aggression principle would not.