This paper is the sequel to a preceding one, in which we studied the so-called abstract Galois theory, as it was formulated by the Portuguese mathematician José Sebastião e Silva (see CLE e-Prints vol. 5(7), 2005). Our purpose is to present some applications of abstract Galois theory to higher-order model theory, to discuss Silva's notion of expressibility and to outline as classical Galois theory can be obtained inside the two versions of the abstract theory, that of Mark Krasner and that of Silva.