Normal monomodal logics can simulate all others

This paper shows that non-normal modal logics can br simulated by certain p olymodal normal logics and that polymodal normal logics can be simulated by monomodal (normal) logics. Many properties of logics are shown to be refle cted and preserved by such simulations. As a consequence many old and new r esults in modal logic can be derived ina straightforward way, sheding new l ight on the power of normal monomodal logic.