James Rachel's three suggested universal values
He accepts that there is a need for society. He does not deny that we are social animals. This then brings up the question, what must human beings accept as morality in order to keep their society functioning?
First, he says there must be a rule which keeps enough infants alive to keep the societyfor becoming extinct. From a societal viewpoint, this is obvious. But is it so from the viewpoint of one individual?
A person who believes that he will always be healthy enough to care for himself, or who believes that once he reaches a certain age it would better that he die, would take a very different stance. So would a person who simply didn't like society. Would he be a sociopath? Or would he just have a different morality?
The problem here is that Rachels has established his own basic moral issue, that society should continue to exist, and then applied it universally in order to prove that there are no universal values except those which support his universal value. In other words he's engaged in circular thinking. A must exist because b exists and b must exist because a exists, round and round you go. I cannot accept his statement that the survival of society is a universal value. Not all human beings would agree with him. As a practical matter, he is correct. A society that does not survive by definition ceases to exist. And that means that he is correct in the evolutionary sense. But if the survival of society is so essential that it has evolved, why couldn't other values? He does not deal with this important point.
Rachels likes to use as an example belief in the earth being a sphere or being flat. He argues that this is different from morality because it can be scientifically proven and therefore is a matter of fact. He then points out that the difference between cremation and cannibalism as a method of burial cannot be proven as a scientific fact. He is wrong. The horrific disease kuru, a form of Jakob-Creutzfeldt disease, in which the brain is eaten from the inside out by mis-formed prions is strongly connected to the practice of cannibalism. This is also a scientific fact.
Another of the essential morals he declares all societies must adopt is the prohibition of, or at least a rule against, lying. The problem is, white lies are often heavily promoted as moral. It is generally accepted in Western societies that is occasionally necessary and moral to tell a lie in order to save someone's feelings. This points out the complexity of the situation. The problem as I see it is that so many of these individuals who are philosophizing about morality are attempting to create nice, simple, clear-cut rules; an on-off button if you will. But in fact morality is a complex and difficult issue which involves many factors which can change from moment to moment. A simple set of rules simply does not exist. Any attempt to find simple rules are doomed to failure. This is not a satisfactory position, but it is realistic.
Of course, he is correct in asserting that a society must have rules about truth. Primatologists and evolutionary anthropologists have concluded that one of the reasons the human brain, and earlier hominid brains, grew so large was to recognize and defend oneself against deceits and lies by fellow members of the troop. Still, this does not exclude other universal moralities.
His final essential morality is a rule against murder. Again, it is hard to argue that such a prohibition is not necessary to maintain a stable society. It has evolutionary value and is likely to be selected for by natural selection.
My critique of Rachel is that he is too limited in recognizing moral imperatives. He clearly wants a simple set of rules to keep things from growing complicated and messy, but this is a denial of the reality of the competing needs and desires of individuals and even of competing moral beliefs in one individual.
Evolution has made compromise after compromise and approximation after approximation in our bodies, our senses, our brains, and our moralities. Ignoring this confusion to seek clear answer only makes sense if we assume humans were designed from scratch by a brilliantly gifted bioengineer. Reminder: we weren't. We are the result of random mutations and natural selection. We're a mess.