The intellectual`s function in the second half of the 19th century is that of critical intervention in society. Based upon this conception, the objective of this thesis is to analyze Eça de Queiroz`s role as an intellectual in his project to modernize Portugal. It also aims to identify the writing procedures employed by the author in his proposal to change the current situation. In addition to the analysis of Queiroz`s criticism to Portuguese society, the essay presents a brief overview about the European social and cultural context in the 19th century, in order to discuss the inferiority of Portugal in relation to the modern capitals of Europe. The investigation focus on one of his main novels, O primo Basílio, published in 1878. In this book, Eça de Queiroz criticizes Portuguese bourgeoisie, which was, according to the author, defined by its hypocrisy and the desire for a social rise. This discussion will become wider through references to other texts written by Queiroz, specially his articles and personal letters, and by other authors, which will provide the historical, critical and theoretical support to the analysis.