"What is the meaning of the term ‘human’ in the phrase ‘human rights’?" (Politics II Q2, 2013)
Many political and moral arguments can depend on how one defines what constitutes a living human being. For instance, pro-life activists argue the unborn fetus is a living human being thus to kill it through abortions constitutes murder. Similarly it is considered wrong to euthanize severely mentally handicapped individuals because they are still human beings. Conversely euthanizing, experimenting on, and caging chimpanzees and other apes is allowed because they are considered not human. However, medical & biological science has made it much harder to tell what should be considered a human and whether that individual is alive or whether they are deceased.
Before the emergence of genetics, physical traits and
mental abilities were thought to distinguish humans from non-human
animals. Individually this is typically not true, other apes have
opposable thumbs, hippopotamuses are hairless, ostriches walk on two
legs, dolphins can recognize their reflection and have names, parrots
and apes are able to learn language, crows and chimps make and use
tools, dogs can use logic etc... Likewise there are human beings which
do not have these traits: birth-defect can take away one's arms and legs,
genetic diseases can cause excessive hair-growth, strokes can remove
the ability to use language, movement disorders (eg. Huntington's
disease) can prevent a person from using tools. Finally, neurodevelopmental disorders can reduce a patient's ability to learn below that of some animals.
Genetically, Homo sapiens is a species of Great Ape which is sufficiently similar to the 'average' human reference genome that it falls between boundaries based on the HapMap project which gathered genetic data from a variety of human populations across multiple continents. This is a pretty robust definition but not as straight forward as it seems because the human genome changes slowly leaving much of it identical to that found in chimpanzees (95-99%) and even mice (~80%). Furthermore some genes are so diverse in humans that each version is more similar to the analogous version in chimps than it is to different human versions. In addition, humans can be quite different from each other genetically, with some even having extra copies of chromosomes (eg. Downs syndrome sufferers have an extra chromosome 21).
However, a purely genetic definition of a human is extremely problematic. For instance extensive biological research is done using Hela cells which are named after Henrietta Lacks the person from whom they were isolated in the 1950s. If we were to use a genetic definition of human then she is still alive and living in countless research laboratories across the world despite dying soon after the cells were taken. Hundreds of other human cell lines exist isolated from many other people.
Thus additional requirements must be imposed. Many pro-life activists argue anything with the potential to grow into a full individual should be considered a human; but genetic technology has can now reprogram skin-cells such that they are capable of becoming any other cell-type so in theory could grow into a full individual. The more typical definition of a living human as a physiologically independent being (ie. after birth) has issues as well, for instance is a person reliant on a ventilator considered fully alive? This is taken to the extreme in modern medicine as machines can compensate for almost every major organ (heart, kidneys, lungs, etc..) such that a person could be kept 'alive' almost indefinitely. Furthermore some rights (eg. voting rights, marriage rights) are restricted to mentally-competent adults suggesting cognitive ability may be important in defining human-ness. Likewise, extremely mentally ill people can legally have nearly all their rights removed including bodily autonomy (eg. the right to refuse medical treatment).
This creates substantial issues when it comes to severely mentally-disabled patients. Comatose patients are one example, while their body may be perfectly fine they are unable to do anything thing and are may be unaware of their surroundings or of themselves. This suggests they may not qualify as human beings such that letting them die (because they won't feed themselves) is justified. However, a comatose state can also be induced by medications (typically to prevent excessive suffering during healing of extreme traumas) - is this equivalent to temporarily killing someone? A troublingly similar situation arises at the end of many neuro-degeneration diseases, the patient might still be awake and moving but unaware or unable to comprehend what is going on.
Thus there is no single definition of a human being for the application of rights rather it depends on whether other humans think that person deserves that particular right, and most importantly whether their family think they deserve that right.
