In this paper we give a general theorem that describes necessary and su cient conditions for a module to satisfy the so-called Kadison-Dubois property. This is used to generalize Jacobi's version of the Kadison-Dubois representation to associative rings. We apply this representation to obtain a noncommutative algebraic and geometric version of Putinar's Positivstellensatz. We ÿnish the paper by answering questions given by Marshall and Jacobi.