In Paris, the Persians express themselves and elicit the opinions of others on a wide variety of subjects, from governmental institutions to salon caricatures. The difference of temperament of the two friends is notable, Usbek being more experienced and asking many questions, Rica less constrained and more attracted by aspects of French life. Both retain Montesquieu's rich satirical tone, as in Rica's letter 70 (72):
The other day I happened to be in a company where I saw a man who was very content with himself. In fifteen minutes he decided three questions of morality, four historical problems, and five points of physics. I have never seen such a universal decider ; his mind was never suspended by the slightest doubt. They left the sciences, and took up news of the day ; he decided about the news of the day. I wanted to trip him up, and said to myself: I must make use of my strength ; I am going to take refuge in my country. I spoke to him of Persia ; but I had scarcely said four words before he twice refuted me, based on the authority of MM. Tavernier and Chardin. Oh good Lord, said I to myself, who is this man ? Next thing he will know the streets of Isfahan better than I do ! My decision was soon made: I said no more, and let him talk, and he is still deciding.
Although this takes place soon before the death of the aged king, much of what he has accomplished is still admired in a Paris where the Invalides is just being completed and cafés and theatre proliferate. We observe the function of parliaments, tribunals, religious bodies (Capuchins, Jesuits, etc.), public places and their publics (the Tuileries, the Palais Royal), state foundations (the hospital of the Quinze-Vingts (three hundred) for the blind, Invalides for wounded veterans). They describe a buzzing culture, where even the presence of two Persians quickly becomes a popular phenomenon thanks to the proliferation of prints (letter 28 [30]). The café – where debates take place (letter 34 [36]) – has become established as a public institution, as were already the theatre and opera. There are still people foolish enough to search at their own expense for the philosopher's stone; the newsmonger and the periodical press are beginning to play a significant role in everyday life. Everything from institutions (the university, the Academy, Sciences, the Bull Unigenitus) to groups (fashion, dandies, coquettes) to individuals (the opera singer, the old warrior, the rake, and so forth) comes before the reader's eye.
Usbek for his part is troubled by religious comparisons. Though it never occurs to him to cease being a Muslim, and while he still wonders at some aspects of Christianity (the Trinity, communion), he writes to austere authorities to inquire, for example, why some foods are considered to be unclean (letters 15–17 [16–18]). He also assimilates the two religions and even all religions with respect to their social utility.
Certain sequences of letters by a single author develop a particular subject more fully, such as letters 11–14 from Usbek to Mirza about the Troglodytes, letters 109–118 (113–122) from Usbek to Rhedi on demography, letters 128–132 (134–138) from Rica on his visit to the library at Saint-Victor. They sketch numerous analyses that will later be developed in L’Esprit des lois for subjects such as the types of power, the influence of climate, and the critique of colonization.
