OK, this is my take on consciousness, life, animals, abortions and euthanasia.
One issue is what is it that we mean when we talk about human life? Why do we place an especially high value on it? Is what we value human life itself or something associated with it? Are there other life forms that we should value in the same way and to the same degree that we value human life?
The other issue is autonomy. What rights do we have to control our own bodies and our own lives? Can we end them whenever we wish? Do we have the right to control our own bodies to the extent that we can expel another life form no matter what the consequences to that life form?
I'll deal with autonomy in matters of life and death first. The general principle is that one should have control over one's life and one's body. Exceptions have to have strong justifications.
For the sake of arguments concerning autonomy I will concede the pro-life position and regard a fetus as a person. (In fact I disagree with this position.) Bearing a child is still a major intrusion on the mother's autonomy. Usually it is a sought and accepted one. Sometimes it is an unsought and resented one.
Most of us would agree that we have an obligation to preserve a human life unless there are other factors involved. Some would say that we have no such obligation to a stranger. I think this belief is dangerous to a society, undermining the empathy that is at least part of the basis of the parts of morality concerned with relations with others.
Most of us would also agree that there are limits to this obligation. One is not obliged to impoverish oneself, or accept maiming or significant risk to one's life to preserve the life of someone that one feels no bond with other than that of our common humanity.
I think that allowing such an intimate use of one's body as is required by pregnancy is beyond one's obligations to another. There needs to be something else involved to create such an obligation.
In the case of a pregnancy due to rape there is clearly no such extra source of obligation. A pregnancy due to rape is a continuation of the rape. There is no consent that could be used as a basis for any claim of assumed commitments. An abortion in this case is a form of self-defense. The fetus is the means by which the rapist continues his attack. Most people would agree with this position. The closest analogy I can think of is a human shield used by someone who is firing at you. If you kill the human shield in the process of defending yourself you are not morally responsible for the death of the shield – the hostage taker is.
Many claim that consent to sexual intercourse implies consent to any pregnancy that results from it. While this is a defensible position I do not agree with it. It is not obvious enough to use as a basis for any laws. A law should not command an act that a reasonable person could see as immoral. A reasonable person could see preventing a woman from obtaining an abortion as an immoral act and I would see it that way. I might agree with this argument if I saw the fetus as a person but I would not support any laws banning abortion. They have the potential to tear society apart.
The claim of autonomy implies that one has the right to choose the time and manner of the end of one's life. In other words one has the right to commit suicide and the right to ask another to help in carrying out a suicide. One does not have the right to demand such help from others.
However there are complicating factors surrounding suicide. The most important of these is the fact that many, probably most suicide attempts happen when someone is in an abnormal state of mind. The other is the effect that suicide has on other people especially those close to oneself.
Most suicide attempts are made by someone suffering from despair. Usually this is because of of something that can be remedied by help or by time. If they are stopped from killing themselves they will usually eventually be glad that they were stopped. And their suicide usually causes grief to family and friends.
One reason why people commit suicide is mental illness. Another is temporary despair and lack of sense of proportion in adolescents. Another is an exaggerated sense of responsibility – men committing suicide after business failures for example. None of these are good reasons for committing suicide. Allowing someone to kill themselves for such reasons is to make a fetish of autonomy and the idea of rights rather than valuing actual individual people. It is allowing people to die because they made a momentary error, because they were down. They certainly should not be helped to kill themselves the way some euthanasia advocate suggest. Adolescents and the mentally ill do not have the full rights of an adult in their right mind and someone or other has a duty of care towards them. Thus I believe that any argument based on rights for allowing such people to commit suicide fails.
But sometimes there are good reasons to commit suicide. The principal ones are unendurable pain and suffering. Palliative care can do a lot but it has limits. Sometimes the only way to die with dignity and a minimum of suffering is to commit suicide – to believe otherwise is wishful thinking. If one has a right to kill oneself under such circumstances then one has a right to ask others to help with such a suicide. Thus in principle I support euthanasia.
I believe the case for euthanasia is clearest when someone is dying in pain, is in their normal state of mind and asks to be helped to die. They have a right to try to hang on to life as long as it is worthwhile. This can quite reasonably lead to them delaying their suicide until they are no longer able to kill themselves without assistance. They should have this option. They also should have the option of dying peacefully surrounded by their loved ones rather than having to kill themselves alone.
I believe that the case for euthanasia is also clear when illness or injury puts someone in incurable pain and strips them of their dignity and their mind is clear and they want to die.
I believe that people have the right to make living wills asking that they be killed if they enter certain states and can no longer communicate with anyone. For example they might be in a persistent vegetative state or they might be in obvious suffering but because of brain damage are unable to communicate.
There are obvious dangers with euthanasia but so long as it is restricted to cases where the subject has clearly given consent when they were in their right mind I do not think the dangers are overwhelming.
Many of the opponents of euthanasia seem to value the idea of human life more than they value individual human beings. I believe that our values should be the other way around.
Most people do not make clear distinctions between humans and persons and between life and consciousness. A human being is a member of our species. A person is a self-aware conscious entity. Life is a physical autopoetic process. We do not know the physical nature of consciousness but we can identify such manifestations of it as awareness, emotion and self-awareness.
The only known persons are human beings and probably great apes. These are the only entities that we know are self-aware. As far as we know mammals, birds and reptiles have emotions. I am unaware of any strong evidence of emotions in other animals. We do not know how widespread awareness as distinct from reaction to stimuli is among animals.
All known cases of consciousness occur in living beings but consciousness is not life. Life supports consciousness and gives consciousness a means to act.
The trouble is that when people refer to human life they are usually actually referring to human consciousness. Human life can exist when human consciousness does not. For example when someone is in a persistent vegetative state or when the brain has not yet developed enough to support consciousness.
The the particularly high value that we place on the life of a person has to depend on something that a person has but other life forms do not. Some would say that that thing is a soul. But we do not have proof that a soul exists and if it does exist when it becomes associated with the body. If a soul exists it has to be associated with consciousness not with life itself. There is no reason to believe that any unknown processes or entities are involved with life. Human life is no different from the life of any other organism. It is what that life supports that is different.
So I think the idea that the soul enters the body at conception is implausible. It reduces the soul to being merely a marker. If there is no nervous system to support consciousness then that is it doing? A soul might be necessary for consciousness but only in conjunction with a developed nervous system. It certainly is not conscious by itself.
The existence of the soul is a speculation. The existence of consciousness is a fact. Our ethics and laws should as far as possible be based on facts rather than speculations.
The value that we place on human life depends on the ability of human consciousness to act as a moral agent. And this depends on self-awareness. I do not see a human being as a person until consciousness develops. When does this happen? It's difficult to say because our long term memory of events seems to only start a bit before we are three years old. I would say that self-awareness develops some time after birth but I don't know just when. The best test might be when does a baby or a toddler recognize that the reflection in a mirror is themselves or when it starts to speak. I do not believe that it can possibly happen before four months after birth as this is the earliest time that spindle cells appear and they are probably essential for self-awareness. I suspect that it is several months later.
The great apes seem to be self-aware. There is a strong case for treating them as if they were human infants.
The other mammals, birds and reptiles appear to have at least some of the same emotions as human beings. Since they seem capable of joy and suffering this should be taken into account in our dealings with them. This creates an obligation to avoid causing unnecessary suffering. It does not give them rights. I see rights as a social concept. Since they cannot act ethically and do not interact with us as part of our society rights are an inapplicable concept for them. They cannot recognize or respect the rights of others so it is difficult to claim that they have rights. I do not think that they can be said to have rights if there is no way that they can be said to have obligations. We may kill a mouse whenever we wish to. We should not torture it.
There is no such restriction on what we can do with animals which merely have awareness but not emotions. Pain is not the same thing as suffering. We can treat an animal that is capable of feeling pain but not of suffering in the same way we would treat a plant. This means ants, worms and probably fish.
Just being genetically human does not necessarily make it a person. An early stage fetus with no nervous system is certainly not a person. A toddler who can speak certainly is a person. At some stages in between it is an animal that we may kill if necessary but should avoid causing pain and suffering to. At some earlier stages it is an animal which is aware but has no emotions. The problem is where do we draw the lines? We should err on the side of caution. While birth occurs before a baby becomes a person it is the end of the period in which there can be a good reason to kill it. After birth the greatest intrusion on the mother's autonomy has ended and if the infant is not wanted it can be adopted.
Injury or illness can destroy consciousness partially or totally. If it is totally destroyed this is what is described as brain dead. The person is not actually dead but the things that make that life of value are gone. There is no point to keeping the body alive.
If both self-awareness and the ability to feel emotions are gone but the ability to feel sensations is still there then I believe that morally this is a similar case to brain death. Self-awareness and emotions are the morally significant aspects of consciousness. Sensation and awareness by themselves are not. From the accounts that I have read the Terry Schiavo case appears to be an example of this situation.
The really heart-wrenching situation is when self-awareness and recognition of others are gone but emotions are still there. While theoretically one could treat them simply as animals we really can't or shouldn't. We are confronted with the remnants of a person and inevitably we are seeing the person that was there. I'm thinking of late-stage dementia and similar examples. Our normal compassion leads us to protect what is remaining as long as we can.
If there is some damage but self-awareness is still there then of course they still have a right to live. Damage to mental faculties may however reduce a persons rights to those of a child.
Children while self-aware have less awareness of the consequences of their actions than adults and hence less rights and responsibilities.
Great apes appear to have a subset of the human self-awareness and language abilities. Enough perhaps to put them in the same moral category as a toddler or at most a very young infant.