Babies are important because of what they can become, and that their death hurts their parents in many ways. Humans are important because when they die, you lose a life, years of building knowledge and experience that contributes massively to the lives around them. Cells in a test tube, even a in-vivo, functional human mind, are not morally relevant. I don't believe in the importance of human life, over other life, innately (without my selfish "I like humans to be taken care of"), and cells in a test tube, or a disembodied brain with no life experience are worthless.
One of the doctors I work with has a project that's trying to understand the genetic basis for a specific disease. As part of that project, he has stem cell lines from lots of different families. When they aren't frozen, or being actively used in some test or application, they have to be 'cleaned' periodically ,because the cells, when kept in groups of over a few dozen, begin to differentiate into different kinds of tissue. The phrasing most commonly used is something to the effect of 'They are trying to become a human. Not saying anything causal here, but I find it interesting that our tendency to anthropomorphize extends so far.
I have my own little "theory of morality" that I mostly produced while thinking about how we treat animals as a society, and I think it applies well here. There are two sides to morality, practical morals, the pure concept of value of an action, and empathetic morals, based around the emotions we feel. When we lose a loved one, we mourn the loss of all they knew, of their support, we are sad because that person is gone. When we lose a child, we mourn the loss of the parents, who suffered (half) of nine months, and are fully expecting to be raising a child. We mourn the loss of who could have been, with those lost years. Then we have empathy, the non-practical factor of morality, illogical, we feel suffering ourselves when we see it in the world. When we see, or perceive the pain of another, we feel pain ourselves, and seek to end it for the other, for our own sake. These "minds", incapable of growing into a human, a being connected to society, to their family, capable of holding conversation, inventing, and all those other things. We are able to produce these "minds" with some sugar and a few minutes of cell development, is practically worthless. It doesn't have big cute eyes, or a mouth to speak with, and isn't a "baby" that culture anthropomorphizes in the mothers belly. Empathy, practicality, neither apply, so morality doesn't either. Cells do not deserve moral treatment. ___ Animals: Animals (non-pets) have little practical value. They don't listen to rules. They aren't willing to obey orders, and they have no real working value in the age of machines. However, they provide practical value as eggs, meat, and other goods. Meanwhile, animals have a massive empathetic value. We see their cute eyes, and put human emotions into them, we hurt when we see, or believe we see, the suffering of an animal. So the two drives of morality are at odds, and people start acting strange. Some react by picking empathy, the animals are people, I love them, don't kill them. Some react with practicality. The animals are worthless, meat-factories, hah, that one danced when I shot it in the head. Some balance the two, performing empathetic rituals of sorts, ensuring the animals feel good, have a fast death, ensuring an empathetic compatible style, while fulfilling the practical one as well. ___ I don't know, maybe I'm talking out of my ass, but I really feel like this view of morality works very well, although it's kind of bad at predicting how we should act, more good at explaining why we do. By what criteria do we separate the ethical treatment of humans and animals from sufficiently complex organ structures?
Cells in a test tube, even a in-vivo, functional human mind, are not morally relevant. By that argument, there's nothing wrong with killing humans who aren't useful.Humans are important because when they die, you lose a life, years of building knowledge and experience that contributes massively to the lives around them.
It is impossible to level that judgement in society without all sorts of screwing up, and it's impossible to gauge the worth of a human being with any metric we are aware of today. All people have use in some form, so long as they aren't actively trying to harm, and are participating in society. Even the most poor, after all, can find a home, food, shelter, in the military, where all you must do is use a gun to make a living. The disabled must be cared for as doing so has let us have more productive, more capable, members of society. Accepting people of all forms allows diversity which causes a wealth of ideas and concepts to emerge. And, yes, we treat those less capable as less humans. Children, unable to care for themselves, have fewer rights vs adults. The disabled as well, are forced into mental homes if they are a danger to someone, and so on and so forth. There is nothing wrong with killing those humans who truly aren't useful, those criminals who may feel no remorse and have no ability or will to listen to the laws of society. Even though there is very valid argument to say it's impossible to say who are these criminals in the first place.