The idea of “inurement” in Leopardi is important both in its reflection upon poetry and social life: for example in the Discorso sugli Italiani/Speech on Italians  the fourth part of which opens highlighting this very subject: 

Gli usi e i costumi in Italia si riducono generalmente a questo, che ciascuno segua l’uso e il costume proprio, ... E gli usi e costumi generali e pubblici, non sono, come ho detto, se non abitudini, e non sono seguiti che per liberissima volontà, determinata quasi unicamente dalla materiale assuefazione, dall’aver sempre fatta quella tal cosa, in quel tal modo, in quel tal tempo, dall’averla veduta fare ai maggiori, dall’essere stata sempre fatta, dal vederla fare agli altri ...

Custom and usage in Italy generally reduce themselves to this, that each follows his own custom and usage, ... And general and public customs and usage, are not, as I have said, if not habits, and are not followed but for the freest of wills, determined almost exclusively by material inurement, for always having done that same thing, in that way, and at such time, having seen one’s elders do it, it having always been done, and seeing others do it ...

In the Zibaldone the theme acquires particular importance:

Inurement is a sort of “second nature” [208, 1408, 2402] – it is the cause of our needs [831-2] – “the idea of all proportion, of all convenience, all beauty, of every determined and specific good, and all that is contrary to them, derives from simple inurement” [1183-201, 1212-3, 1259-60, 1306-7, 1568, 1749-52, 3364-5] – it is from inurement that depends good taste in writing [1419-20, 1579-80, 1594] – it is the cause of memory [1508, 1631, 1676, 1716, 2047-8] – the genius “is the absolute son of inurement.”, as is talent [1647, 1661-3] – it is at the foundation of reason and the progress of human spirit, as is demonstrated in the difficulty we have in accepting new opinions [1720-1, 1732] – “to teach is hardly anything other than to inure” [1727] – its strength grows proportionately with  the progress of society [1767, 1922-5] – it is from inurement that derive the effects of literary works, painting and music of well known authors [1832-3, 1871-8] – “Man inures himself in inuring himself” [2028] – “The major part of human talent, and of the intellectual faculties, is the work of inurements” [2571-2] – “generally we call barbarian that which is different from our inurements” [3882-3].