Carlo Cattaneo (Milan, June 15, 1801 – Castagnola, February 6, 1869) was an Italian philosopher, writer and patriot.
Cattaneo was born in Milan; he died in Castagnola, close to Lugano in the Swiss canton of Ticino, where he had spent the last twenty years of his life in exile.
A republican in his convictions, during his youth he had taken part in the Carbonari movement in Lombardy. He devoted himself to the study of philosophy, hoping to regenerate the Italian people by withdrawing them from romanticism and rhetoric, and turning their attention to the positive sciences. In this period, Cattaneo met philosopher Giandomenico Romagnosi and he "was especially attracted by Romagnosi's emphasis on practical solutions and interdisciplinary work". Developing some intuitions coming from his mentor, Cattaneo expounded his ideas in a review founded by him in Milan in 1839, called II Politecnico.
When the revolution of 1848 broke out, he threw himself heart and soul into the fray, and became one of the leading spirits of the insurrection against the Austrians, known as the Five Days of Milan (March 18–March 22, 1848). Together with the young democrats Enrico Cernuschi, Giulio Terzaghi and Giorgio Clerici he formed a council of war which, having its headquarters at Palazzo Taverna in via Bigli, directed the operations of the insurgents. He was second to none in self-sacrifice and heroic resolution. When on March 18 Field Marshal Radetzky, feeling that the position of the Austrian garrison was untenable, sounded the rebels as to their terms, some of the leaders were inclined to agree to an armistice which would give time for the Piedmontese troops to arrive (Piedmont had just declared war), but Cattaneo insisted on the complete evacuation of Lombardy. Again, on March 21, Radetzky tried to obtain an armistice, and Durini and Borromeo were ready to grant it, for it would have enabled them to reorganize the defences and replenish the supplies of food and ammunition, which could only last another day. But, Cattaneo replied: