When, in October 1766, Alessandro Verri left Milan to go to Paris with Cesare Beccaria at the invitation of André Morellet (the translator of Beccaria’s On Crimes and Punishments) and of the encyclopédistes, he concluded an epistolary pact with his brother Pietro. Pietro, who was thirteen years Alessandro’s senior, remained in Lombardy and ensured the preservation of the correspondence by having the letters carefully and systematically copied into large in-folio registers.
After his trip to Paris and London, Alessandro settled in Rome in 1767 and he continued his correspondence with his brother until Pietro’s death in 1797. The time span it covers and its candid take on private and public matters make it the richest correspondence in eighteenth-century Italy. It extends over three decades, from the age of Reforms in Lombardy under the rule of Maria Theresa to the eve of the proclamation of the Roman republic in 1798, and encompasses the French Revolution, the invasions of Piedmont and Lombardy by General Bonaparte, and the creation of the Cisalpine republic.
At first, the brothers’ dialogue preserved the harmony that characterised the discussions held at the Accademia dei Pugni (the ‘Academy of Punches’), the learned society that they had founded in Milan in 1761, and which had been the incubator for two seminal works of the Lombard Enlightenment, namely Beccaria’s On Crimes and Punishments and the Caffè periodical (1764-1766). Yet, the brothers’ apparent convergence of views in the first months of their correspondence could hardly conceal the fact that they were growing apart intellectually.
Pietro’s letters reveal his strong belief in intellectual passions as drivers of historical change, and in the necessity to work towards the happiness of the masses. Throughout his life he remained an ardent reformist and never gave up on his ambition to ‘electrify minds’ through his writings. 
Alessandro’s letters, by contrast, show his individualistic conception of happiness and his wariness of any developments that might upset society’s order and stability (free thought, popular passions), as well as his conviction that attempting to create and shape public opinion was a dangerous endeavour. His refusal to envision a society made up of free individuals – and above all a secular society – alienated him from the spirit of modernity that was emerging at the end of the century.
In 1782, a dispute cropped up between the brothers over the interpretation of Pope Pius VI’s trip to Vienna. The Pontiff had decided to take this unprecedented step to try and dissuade Emperor Joseph II from carrying out a series of religious reforms which would lead to the closure of a number of convents and monasteries, and to the abolition of regular religious orders. Pietro praised the Emperor, whom he saw as an enlightened monarch: ‘To make his people more virtuous, humane, industrious and felicitous, he’s declaring war on superstition, he inspires and commands tolerance, and leads the way towards a time when vice will be stripped of the treacherous veil which gives it the appearance of virtue.’  As for Alessandro, he regarded the Pope’s failure as a humiliation inflicted on the Holy See, but expressed pride at the ‘veneration’ and ‘infinite demonstrations of respect’ displayed by Italian and Austrian crowds towards the Pope during his journey. Those who ‘claim[ed] that their pens commanded public opinion have been proven wrong’, he thought. 
Pietro strove to demonstrate that the political victory of the Emperor was a harbinger of religious regeneration, of the restoration of religion’s social import and public efficacy: ‘Religion is saved, evil is rooted out.’ Above all, he saw this as the outcome of the ‘enduring battle’ waged by a few superior, isolated but victorious minds, in favour of liberties and science. While he clung to Bayle’s belief that ‘no religious opinion is essential to civilian government’,  Alessandro, for his part, regarded religion as part of ‘the arcane foundations of the State […] essential to restrain human passions and refrain the multitude, as we have seen men become fierce and mad when the yoke is broken.’ 
After the French Revolution the epistolary dialogue between the two brothers evolved into overt antagonism, as clearly summed up by Pietro in March 1796: ‘You hate modern philosophers, who have demonstrated that vigorous passions trigger great actions, while I agree with them.’  For Pietro, the 1790s were an exaltated time in an era of political frustration. While he had been disappointed by the reforms carried out by Joseph II in Lombardy, he was filled with enthusiasm for the ideals of liberty and equality proclaimed by the French National Assembly in 1789. However, he understood that the fear awakened by the French Revolution had dealt a lethal blow to the cause of the advancement of reason in Italy: ‘Now that we rightly consider that the dissemination of culture among the people sparked off the events in France, we regard the excess of thought, books, thinkers, advocates of all sorts of doctrines as highly suspicious and we cordially hate them all,’ he remarked in 1794, adding: ‘we live at a time when fierce ignorance is all the rage […]. Reason is losing ground everywhere in Europe.’ 
Alessandro agreed that the revolutionary crisis had been sparked off by the works of enlightened thinkers and he saw this as a vindication of the misgivings he had experienced during his visit to Parisian coteries in the winter of 1766. He was concerned about the way some of the propositions from d’Holbach’s Système de la nature were freely debated in Italy, and he accused the ‘assassin-philosophers’ of undermining the moral and religious principles underpinning civil society: ‘As long as this form of thinking is limited to a few silent men, human society won’t be affected: but as soon as alleged philosophers take their ideas to the streets and ramble freely, human passions will be unleashed, à la française.’ ‘The tyranny of the multitude, the emancipated mob is a monster that I dread much more than Tiberius,’ he added. 
By contrast, the strength in Pietro’s thinking – which was quite original in the intellectual landscape of late eighteenth-century Italy – was to distance himself from the anti-Jacobin zeal of the Lombard élite and to understand that the transition from ‘error’ to ‘enlightenment,’ from tyranny to liberty, could be effected by violent means. For Pietro Verri, the violence in France in 1792 and 1793 could be justified and productive as long as the people managed to put together a constitution. His views echoed those of Beccaria’s On Crimes and Punishments, a work to which Pietro had contributed years earlier: ‘Whoever reflects on the various histories of nations, which after a certain lapse of time come to resemble each other in their main outlines, will repeatedly find a whole generation sacrificed to the happiness of succeeding generations in the hard-fought but necessary transition from the shadows of ignorance to the light of philosophy and, as a corollary, in the passage from tyranny to freedom.’ 
– Pierre Musitelli, École normale supérieure, Paris
 Carteggio di Pietro e Alessandro Verri, 12 vol. (Milan, 1910-1942), vol.10 (1939), p. 237 (my translation).
 2 March 1782.
 17 April 1782; 10 April 1782.
 20 April 1782; 4 May 1782; 22 May 1793.
 13 May 1793.
 5 March 1796.
 1 March 1794; 29 march 1794.
 25 August 1794; 15 December 1792.
 C. Beccaria, On Crimes and Punishments (Cambridge, 1995), p. 106-107.