[en] Before the great Lisbon earthquake of 1755 the continental part of Portugal had already experienced strong, catastrophic tremors; present day seismotectonic maps show that indeed the metropolitan area of the capital city, as well as the south-western and southern coastal areas of the country are the most risky ones. Earthquakes have always been a matter of great concern among the communities living there, causing fears and phobias that have been transmitted from generation to generation. In this paper an attempt is made to look for signs of change or of continuity shown by people in Portugal with regard to the effects of earthquakes that have occurred there since ancient times. Special attention is given to the eschatological interpretations of tremors, the first to appear, that were gradually replaced in the 18th Century by explanations that invoked heavenly, primordial causes and/or natural, secondary causes in discussing the origin of such phenomena. It was after the Lisbon earthquake in 1755 that experimentation was called in to explain them, first in a rhetoric way and then, in the 19th Century, in scientific terms; seismology was then born. In Portugal, although a copious literature does exist concerning such interpretations, a pragmatic attitude towards earthquakes has always prevailed in the sense that it has always been more important to mitigate their effects, particularly the effects on public health in the case of the Lisbon earthquake, than to look for their exact causes.

[es] Con anterioridad al gran terremoto de 1755 ya se hab?an registrado en Portugal temblores de tierra de intensidad bastante significativa. En la actualidad, las cartas sismotect?nicas ense?an que tanto la regi?n de la Gran Lisboa, como la costa sur atl?ntica y costa algarvia son las que presentan mayor peligrosidad s?smica. Los temblores de tierra fueron desde siempre un asunto de preocupaci?n para la poblaci?n portuguesa que habitaba estas regiones, provocando temores y fobias que fueron transmitidos de generaci?n en generaci?n. En el presente trabajo se procura identificar las se?ales de cambios o de continuidad en la poblaci?n portuguesa y las reacciones ante los efectos de los terremotos que desde tiempos remotos afectaran al pa?s. Particular atenci?n es atribuida a las interpretaciones de ra?z escatol?gica, las primeras que surgieron y que gradualmente fueran sustituidas en el siglo XVII por explicaciones que invocaban la existencia de causas primeras (divinas) y causas segundas (naturales) en la discusi?n de este tipo de fen?menos. Va a ser con el terremoto de Lisboa, en 1755, cuando la experimentaci?n surge como medio de explicaci?n, inicialmente apenas en t?rminos ret?ricos, para despu?s, a partir del siglo XIX, en t?rminos cient?ficos, sustentar la aparici?n y desarrollo de la propia sismolog?a. En Portugal, mientras exista un copioso acervo bibliogr?fico en lo que concierne a las referidas explicaciones, una actitud pragm?tica ante los terremotos ha prevalecido siempre, en el sentido de que es siempre m?s importante mitigar sus efectos, particularmente los efectos en la salud p?blica en lo que se refiere al terremoto de Lisboa, que determinar sus causas exactas.