The thousands of researchers and teachers that participated in the 25th International Congress of Mathematicians – the first one held in Spain –, found a half-empty city because of the summer diaspora, but full of expressions of the vigorous growth that has turned it into the third economic center of Europe, preceded only by London and Paris. For many years now, Madrid’s strength has been outstanding: if the entire Spanish economy has benefitted from freedom and from Europe – economic growth and deep-rooted democracy have gone hand in hand –, that of Madrid stands, refuting many old and new topics, as the best instance of a Spain that is open to the world, after wrapping up a long process of secular modernization. Madrid, which contributes 18% of its GNP and has a per capita income that exceeds the national average by 35%, now heads the growth of the Spanish economy and is the basic platform of its increasing internationalization... [+]