Concepts are important as thinking tools at all levels be it academic, practical or legal philosophy. The three basic doctrines of legal positivism are : Pedigree Thesis or say Social Fact Thesis which emphasize that it is a necessary truth that legal validity is ultimately a function of certain kinds of social facts. The second doctrine of Conventionality Thesis claims that social facts give rise to legal validity and are authoritative in virtue of some kind of social convention. The third and the most important doctrine is Separability Thesis which further states that law and morality are conceptually different. Judges cannot incorporate moral requirements into law, they can only consider moral requirements in resolving certain unsettled questions of law but according to law. The most important questions of Analytical jurisprudence are "What are laws?" What is the relationship between Law and Power, Law and Morality.