Full Idea
Hart replaced Austin's concept of positive law as sovereign command with a more democratic ideal. In modern law-based societies the authority of law depends on the people's acceptance of a law's enduring validity.
Gist of Idea
Hart replaced positivism with the democratic requirement of the people's acceptance
Source
report of H.L.A. Hart (The Concept of Law [1961]) by Jens Zimmermann - Hermeneutics: a very short introduction 6 'Hart'
Book Reference
Zimmerman,Jens: 'Hermeneutics: very short introduction' [OUP 2015], p.103
A Reaction
Presumably the ancestor of this view is the social contract of Hobbes and Locke.