Abstract: Causal perturbation theory was developed by Stueckelberg and Bogolyubov in the 1950s and perfected by Epstein and Glaser in the 1970s, leading to a consistent elimination of UV divergences.  During the last decade Scharf and collaborators have applied it to gauge theories and, among other things, proved that gauge couplings and ghosts arise as consistency coditions in this formulation.  I will try to give a survey of this approach without many technical details, since it seems that these results have been overlooked by most active theorists, and give a better motivation of BRS symmetry.