Thirty-five collaborators were selected to contribute to this volume of essays commenting on the important events that occurred in the period 1930-1960 in the areas of their specialties, with the admonition that they should point out in which way their special fields developed so as to benefit the nation or not to benefit it. The first contribution is a valuable chronological guide for the period from October 12, 1928, to October 1, 1960. This is followed by the longest essay in the book by far, a historical account of the same period by Tulio Halperín Donghi. For the most part the remaining essays are exceedingly short, usually of fewer than ten pages. They include developments in the field of demography, changes in governmental powers in their various aspects, political parties, labor organization, armed forces, foreign relations, agriculture and stock-raising, industry, commerce, economics and finances, history and sociology, philosophy, science, medicine, education, public works, architecture and urbanization, radio and television, motion pictures, sports, journalism, painting and sculpture, theater, music, literature, religion, and human rights. The essays are very uneven in character. Some minimize the Peronista period while others naturally emphasize it. Short biographies of the collaborators indicate that in general they are experts in their fields.