Final answer:
The doctrine that suggests some moral norms are universally valid is referred to as moral universalism. It is opposed to normative ethical relativism, which states that morality varies from society to society. Universalism maintains that certain ethical truths are applicable to all peoples at all times.
Step-by-step explanation:
The doctrine that some moral norms are valid for everyone, or universal, is known as moral universalism. Unlike normative ethical relativism, which posits that moral rights and wrongs vary by society, moral universalism suggests that there are moral standards that apply universally, transcending cultures and individuals.
Moral universalism is often contrasted with the theory of Normative Ethical Relativism, which holds the view that what is right or wrong is determined within the cultural or social context, and not by any universal ethical standards. Despite the popularity of ethical relativism, partly due to acknowledgement of the diverse customs and laws across different societies, universalism supports the idea that some moral truths are valid at all times and in all places, akin to the universal application of mathematical truths.
Philosophers like Immanuel Kant have pursued rational, universally applicable ethical principles. Kant's universal law formulation, for example, insists on the universalizability of moral laws. The search for a moral foundation through reason has been an endeavor since Socrates, striving to find ethical principles with universal application. This quest challenges both the immutable edicts of moral absolutism and the situational dictates of ethical relativism.