A human being does not equal a person and a person does not equal a human being. A person is someone who is aware if themselves, their future, their on-going life. Someone in a Persistent Vegitive State has no awareness of these things and therefore is not a person but is still human because they are made of human tissue; similarly persons may not be humans, like apes, dolphins and whales with higher intelligence. With abortion, however, the embryo has no sense of person but that does not diminish the idea that they have a potential life, there is an impending personhood so therefore makes it wrong to abort because it is taking away their opportunity to develop their person.
In the case of abortion science can only give a rough estimate to when life begins; something is generally defined as being alive if it is a complex system that is self-replicating and self-determining. It is then said to be conscious if it responds to the environment appears to do so in a way that implies choice. An absolute right would be to say that murder is wrong because everyone has a right to life but the difficulty would the determination of when the personhood comes into account to which the right can be applied. Science, Joseph Fletcher and John Locke cover slightly different but wholly similar views to when personhood comes into account; Science and John Locke’s definitions are more rational and with reason whereas Joseph Fletcher’s is like his approach to ethics, dependable upon situations.
The Ancient Greek philosophers agreed that if a life was valueless, for example-deformed infants, it was a duty to kill the infant. Christian’s take the view that we are property of God, He gave us life and therefore only He is allowed to take it away. Thomas Aquinas in fact said that killing a human is a sin against God, which would give every human the right to live, therefore making the right to life an absolute right. This view, however, could be taking a bias view to the Homo Sapiens species. As someone in a PVS or an embryo who has no value or quality of life has more of a right to life than a non-human species with personhood such as whales, dolphins or higher intelligent apes.
Utilitarianism takes the view a person essentially has desires of his or her future, but as we die our desires die with us. Killing the person eliminates the happiness the victim could have had by fulfilling their desires which would not be achieving the greatest happiness.
Preference utilitarianism has to take into account a victims preference to live; it is more against a person being killed than a human being. A person will have desires and preferences to live on and fulfil their desires or ambitions and therefore it is wrong to take away their right to life as these will not be satisfied. Due to the fact a person is highly future orientated it is wrong to take away their potential future by killing them as it is their preference to live, however a human being with no personhood (brain stem dead) has no self awareness of his or her future and therefore it is doing no wrong by killing them as they have no preferences of this sort. This approach to the right to live is taken as a dependent right on the personhood of the being.
If a person is unconscious or asleep it could be seen as them losing their right to life, as they are unaware of being murdered and therefore will be unconscious to the fact that their desires will not be fulfilled and they will not fear the impending lack of fulfilment of their desires. The prior existence view is that maximising pleasure and increasing pleasure of all those around you to share out the good.
