I do not know of any conclusive argument that demonstrates the existence of a single, ultimate interpretation of good which applies to everyone. However, rationality can certainly help us clarify these issues. All ethical fields must be based on what is . They must take specific facts of a reality as a starting point. Descriptive ethics may go beyond that to formulate general theories of human conduct what motivate us, and why we behave the way we do.
Most theories claim to have predictive power.
Such systems are inherently predictive. It makes no sense to talk about should do if there are no option open to us. While much of what we do can be explained at the lower level, a more comprehensive account must be formulated at a higher level of abstraction - such as values, thoughts, choices, etc. It is strange that while most researchers are happy with environmental explanations, they reject cognitive ones even though both ultimately reduce to material causes. Scope Moral inquiry cover both group as well as individual behavior.