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. He resided at the Palazzo Gavazzi from 1840 until 1848.
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:
The enemy having furnished us with munitions thus far, will continue to do so. Twenty-four hours of victuals and twenty-four hours of hunger will be many more hours than we shall need. This evening, if the plans we have just arranged should succeed, the line of the bastions will be broken. At any rate, even though we should lack bread, it is better to die of hunger than on the gallows.
On the expulsion of the Austrians the question arose as to the future government of Milan and Italy. Cattaneo was an uncompromising republican and a federalist; so violent was his dislike of the Piedmontese monarchy that when he heard that King Charles Albert had been defeated by the Austrians, and that Radetzky was marching back to reoccupy Milan, he exclaimed:
Good news, the Piedmontese have been beaten. Now we shall be our own masters; we shall fight a people's war, we shall chase the Austrians out of Italy, and set up a Federal Republic.
When the Austrians returned, Cattaneo had to flee and took refuge in Lugano, where he gave lessons, wrote his Storia della Rivoluzione del 1848 (History of the 1848 Revolution), the Archivio triennale delle cose d'Italia (3 vols., 1850–1855), then, early in 1860, he started publishing the Politecnico once more. He strongly opposed Cavour for his unitarian views, and for the cession of Nice and Savoy. In 1860 Garibaldi summoned him to Naples to take part in the government of the Neapolitan provinces, but he would not agree to the union with Piedmont without local autonomy. After the union of Italy he was frequently asked to stand for parliament, but always refused because he could not conscientiously take the oath of allegiance to the monarchy. In 1868 the pressure of friends overcame his resistance, and he agreed to stand, but at the last moment he drew back, still unable to take the oath, and returned to Lugano, where he died in 1869.
As a writer, Cattaneo was learned and brilliant, but some view him as being too bitter a partisan to be judicious, owing to his narrowly republican views; his ideas on local autonomy were wise, but, at a moment when unity was regarded as an absolute requisite, they were deemed inopportune.
- Antonio Gili: Castagnola in German, French and Italian in the online Historical Dictionary of Switzerland..
- Filippo Sabetti, Civilization and Self-Government: The Political Thought of Carlo Cattaneo, Lanham, Lexington Books, 2011, p. 30.
- Simone, Gabriella Anedi de (2003). Milano nei palazzi privati: cortili, giardini, salotti. CELIP. p. 258. Retrieved 12 September 2012.
- Colussi, Paolo; Luraschi, Francesco (27 December 2007), Cronologia di Milano dal 1841 al 1850, Storiadimilano, retrieved 2008-09-14.
- This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press