 A complex web of relations might connect these various concepts. Hart’s theory does yield a ground of law, and hence a doctrinal concept, from his sociological or taxonomic concept. What makes a proposition of law true, for Hart, is its pedigree which must trace back ultimately to the rule of recognition in the community. Similarly, we might create a taxonomy by considering how the grounds of law differ from the grounds of morality or religion. A taxonomy, that is, follows directly from comparing truth conditions for propositions of law to truth conditions for propositions of morality. 