Relativism is the part of meta-ethics. It is discussed widely out from the philosophical. This topic is controversial among philosophers and non-philosophers. Some philosophers are quite critical about the relativism. But other philosophers favor the formation of the moral relativism. It was not so much hot topic among philosophers in the 20th century.
Thus capital punishment is a different moral question for Nomadic peoples who were living in tents. So that the societies need more security prisons involved the relativism.
