In Paris in 1929, he published the first version of his fundamental work, "The theory of protectionism and international exchanges" at the Giard publishing house (as part of the "Bibliothèque Économique Internationale" collection). His intense advocacy of industrialization formed the main theme of the book "The role and destiny of Romania's bourgeoisie" (1942), which was one of the main works dealing with the development of a local middle class, alongside those written by Ştefan Zeletin and Eugen Lovinescu (while sharing some perspectives with the essays of Emil Cioran); the topic blended with his support for authoritarianism and the one-party system, as Manoilescu rejected democracy (which, in his view, encouraged the majority-forming peasantry to decide on matters that did not concern it). "The role and destiny..." criticized the course of Romanian social development: