From the comment:
However I believe the application of the argument is limited.. As it doesn’t address the contested questions such as definition of when life begins. As such your ‘hierarchy of importances’ only follows if the assumption is make that life begins at conception.
I think an issue the post doesn’t consider, is the greatest potential of the woman and man who will be caring after the child when they are born. If the child/fetus in the womb is found to be severely deformed and close to a vegetated state, which will involve a lifetime of the most basic care for their needs, it will mean the life of the carers will be such that the large part of it will have to be devoted to looking after a child that may not even comprehend who their own parents are.
I believe that taking your own argument of the greatest potential, it can be argued that the child given in the above example has less potential in having something resembling ‘life’, than the potential life/lives lost of their carers.
Science depends on the study of events that can be observed by different observers in different labs, under similar conditions.
The one-celled embryo, the zygote, is unique in that the products of two cell lines, a sperm and an egg, which are at the end of their life cycle, combine to form the beginning of a new life cycle. Any argument in favor of potential is only a personal belief, inconsistent with observable facts. We know that fertilization is a point that a technician can identify in the in vitro lab. No one implants unfertilized eggs. In fact, we can watch the changes by serial ultrasounds and blood hormone levels that result from the new embryo.
Philosophy can utilize the same criteria: what would happen in another place if the same value were given to another child at another age? Why not kill the child with less “potential” after birth?
Sasha gives a classic example of utilitarian ethics: the greatest good for the greatest number, without regard to individual, inalienable rights. Utilitarianism allows fickle, faddish and selfish motives or might makes right to determine the safety that each of us can expect from society and law.
Anyone is at risk of becoming like the human in the example Sasha gives: a fall, a bad allergic reaction, an assault could leave any of us at least temporarily or permanently dependent on others for “the most basic care for their needs.” Why not snuff out the life of these people?