The concept of law as a functional concept

In her book Positivismo jurídico "interno", Cristina Redondo claims that legal theory can be neutral from a moral point of view. An essential part of her argument is based on the criticism of an anti-positivist conception of law developed by Fernando Atria according to which, since law is a functional concept, no descriptive or morally neutral theory of law can be provided. The essay claims that, while Atria's conception of law encounters some difficulties, Redondo's criticisms miss the mark leaving their impact inconclusive. More importantly, there are two kinds of natural law theory that also claim that law is a functional concept but that do not face Atria's difficulties. One such theory seems particularly suitable for avoiding not only Redondo's criticism but also standard objections from the positivist camp. If this type of theory is correct, a theory of law cannot be morally neutral