The Third General Conference of the Latin American Episcopal Council met in Puebla (Mexico) in 1979 with the theme: Evangelization in the present and future of Latin America. It continued the path of the previous Conference in Medellin, reiterating the option for the poor and the liberation, and the importance of the Ecclesial Base Communities (CEBs). Among the issues addressed by Puebla are ideologies, especially capitalist liberalism, Marxist collectivism, and the doctrine of national security. These were times of the Cold War, of strategic disputes and indirect confl icts between the United States and the Soviet Union, and its zones of infl uence, covering Latin America. One of the questions of that time is whether a Christian can be Marxist and adopt his analysis for the understanding of social reality. The provincial Jesuits put this question to their general superior, Father Pedro Arrupe, who based on extensive research and the conclusions of Puebla wrote a letter on Marxist analysis. This letter reveals a clear perception of the signs of the times and a prophetism in the line of the Second Vatican Council, with elements valid for the present times.