This article examines a metaphoric theme-cast as "CONTROL OF AN UNPREDICTABLE/UNDESIRABLE FORCE IS A RIDER'S CONTROL OF A HORSE" -and its linguistic instantiations in English and Spanish. Examples of these instantiations are taken from a number of different sources to show how the metaphor is used in everyday language to talk about the restraint of different processes. It is found that the metaphor has a wide scope, with the metaphoric source mapping on to a variety of processes, which may be internal (like emotions or thought) or external (like events or other people). These linguistic metaphors have been used in these 2 European languages for centuries, and their continuing currency in talk about contemporary social concerns is somewhat surprising, given that the source domain that informs the metaphor is marginal in modern industrialized countries. The survival of this metaphor in two linguistic systems is discussed in relation to the convergence of a number of factors, in which the authority of the source of transmission is seen to have played a crucial role in its propagation throughout two speech communities. (Fiona MacArthur)