The US government recently announced that it was lifting its moratorium on funding certain experiments that use human stem cells to create animals that are partly human. At present scientists are only interested in creating entities with some human qualities, but which remain “mostly” animals. For example, some scientists want to create a chimeric pig with a human-enough heart to transplant into a human.
Distinguishing between humans and other animals is common in most cultures and is certainly central to Western intellectual and religious traditions, so the idea of a part-pig part-human is very unsettling to many people. Warnings about the dangers of mixing animals and humans are also a classic theme in Western culture with novels like the Island of Doctor Moreau by H.G. Wells.
We can all agree that the world is not ready for a talking pig, and there is clearly a dystopian novel waiting to written about the pig given human consciousness but without the ability to interact. Moreover, an entity with a human body but a pig brain, which would be useful for human transplants, would certainly be controversial. But, what would make one of these entities human and another not human?
There are three major definitions of a human in Western thought. The first is based on Christianity, following Judaism, and concludes that a human is that which is made in the image of God. The second, based in biology, is that a human is that with a human DNA sequence, and this sequence is largely shared with other animals. The third is based in philosophy, which is that a human is that with certain capacities like consciousness and rationality. (Philosophers call this personhood.)
Those who believe humans are made in the image of God would be opposed to chimeras because one of the central themes in the Christian narrative is that humans were created to be distinct from the other animals. Those who would define humans by their DNA would probably not inherently oppose chimeras because DNA sequences are already shared with other animals, and, biologically, we are just another animal. Finally, the definition based on capacities would generate opposition if the chimera had some important human capacity. From this view, having a human pancreas does not make a pig human, but a pig able to voice opposition to having their pancreas removed would be human.
Much of the concern with chimeras is with creating entities with ambiguous human status, like the pig with some human-like cognition. If we create an entity that is considered “human enough,” then our intended purpose for such an entity – such as harvesting their organs – would be “dehumanizing.” We would not be treating them like the humans they (ambiguously) are. Thus, the government is closely regulating experiments that could change anything in the brain of animal, for fear that we could create human-like behaviors in them.
Besides the risk of dehumanizing the chimeric entities, other critics are concerned that creating chimeras would actually dehumanize the present human population. Present humans would be dehumanized by the mere discussion of chimeras. Critics claim that the philosophical definition of a human teaches us that we are of unequal value, and that the biological definition teaches us that we are like animals, and can be treated as such.
Other concerns are that chimera research focuses on the capacities of the chimeras, such as whether they would have human levels of rationality. This teaches us that humans are those with rationality. If the public thinks that a human is a compilation of capacities, those existing humans with fewer of these valued capacities will be considered to be of lesser value. As critics note, this was the logic of the eugenics movement.
Similarly, chimera research teaches us that there is not much of a distinction between humans and other animals. Critics are concerned that if we think of humans as just another type of animal, like a pig, we will in an extremely small and subtle way begin to treat existing humans like we currently treat pigs – which is obviously not good given how many animals we eat. It has been shown that members of the public who believe in extreme versions of the biological and philosophical definitions of the human view existing people as having less intrinsic value, and are also less concerned with human rights.
Society should debate whether to create chimeras like pigs with human qualities. But, we should also be aware that how we talk about humans during this debate may inadvertently change how we look at ourselves. Perhaps some simple counter-programming is in order. In my view, people who say humans are like animals should also say we should not be treated like how we treat animals; and people who say we are compilations of capacities should say that those with fewer capacities have no less value than those with more.