In this paper I will analyze the impact of Spencerism on Brazilian intellectual history at the end of the 19th Century and beginning of the 20th Century. The diffusion of Spencerism in Brazil, in the beginning of the 1870’s was simultaneous to the diffusion of Darwin's theory. Nevertheless it did not have the same opposition suffered by Darwin. On the contrary, it was embraced by those who were looking for a theory for the Brazilian society, and had a great influence in the Brazilian intellectual scene. At that time, one of the most distinguished figures in the intellectual milieu, Silvio Romero, sought such theory through the analysis of the literary production of the country. Romero was a philosophy professor at D. Pedro II School, a journalist and a member founder of the Brazilian Academy of Letters. In 1888 he published the History of the Brazilian Literature in five volumes, where he affirmed, in the introduction, that he would interpret the Brazilian literature scientifically, or "a la Darwin", although he considered Spencer’s theory the best one to base his interpretation. In this book, Romero failed to distinguish between the history of Brazilian literature and the history of Brazil, and recognized the fusion of the races as a characteristic of the evolutionary formation of Brazil. He observed, "The American races are a product of the American environment." In a country formed by different ethnicities, the debate among intellectuals revolved around the question: who was the real Brazilian? That was a racial question since the country, just issued from the condition of slavery, was faced with the image of three races. Spencerian intellectuals like him were polygenists, and thus, in the “struggle for existence” the victory would be of the “most adapted”. Although presenting themselves as Darwinian intellectuals, as in the case of Silvio Romero, the polygenists professed Spencerian ideas that Darwin would have never accepted. According to the anthropologist Luiz de Castro Faria, Darwin would never be a Darwinian, still less a social Darwinian in Brazil. Silvio Romero, on the other hand, expressed for the evolutionism his position in relation to positivism, theory widely spread in the country. In 1894, he published the book “Doctrine Against Doctrine – Evolutionism and Positivism in Brazil” where he opposed Evolutionism and Positivism, criticizing the last one that, for him, dominated the political ambience of the country. He affirmed that he was opposing Spencer to the dogmatic positivists, yet he opposed one form of positivism to the other, considering that Spencer was also a positivist. We find Spencer ideas not only in the historian milieu. In the 1930s, Spencer was an inspiration to Lourenço Filho, who was the author of a great Education project in Brazil, which aimed at a continued education for all, without punishments, secular, and introducing the science education in schools.