Final answer:
The ethical position that deems a behavior as valid when applied universally is known as the universal law formulation of the categorical imperative, articulated by philosopher Immanuel Kant. Contrarily, Normative Ethical Relativism posits that moral values vary across societies with no universal ethical standards.
Step-by-step explanation:
The ethical position that argues a behavior is valid if you're willing to apply it universally is known as the universal law formulation of the categorical imperative. This conception of morality was famously articulated by Enlightenment philosopher Immanuel Kant. Kant's principle of universality posits that an action is moral if it can be made into a universal law that all rational beings would follow. In essence, an act is only right if one would wish it to become a universal norm for everyone.
According to Kant, a maxim (or rule of action) is ethical only if it can be willed to be a universal law without contradiction. This means that if the maxim were to be applied universally, it should still lead to a coherent and functional society. For example, lying cannot be universalized because if everyone lied, trust would be destroyed, making it impossible for any lie to achieve its purpose.
On the contrary, Normative Ethical Relativism challenges the idea of universal ethical principles, holding that moral rightness and wrongness vary by society, and there are no absolute universal standards. This position emphasizes the diversity of moral practices across cultures and denies that there is a single correct way to act ethically.