We introduce the notion of a severe right Ore set in the main as a tool to
study universal localisations of rings but also to provide a short proof of P.
M. Cohn's classification of homomorphisms from a ring to a division ring. We
prove that the category of finitely presented modules over a universal
localisation is equivalent to a localisation at a severe right Ore set of the
category of finitely presented modules over the original ring. This allows us
to describe the structure of finitely presented modules over the universal
localisation as modules over the original ring
