"Conflict and harmonies of races in America" is, perhaps, Sarmiento's most controversial book. In it he declares that "the Indians do not think because they are not prepared for it, and the Spanish whites had lost the habit of exercising the brain as an organ." On the contrary, he describes an American people exempt from all intermingling with races inferior in energy, their political traditions preserved, not degraded by the adoption of race ineptitudes for government.
There are several factors that come together in the writing of this, his last work: the influence of Spencer, Taine and Darwinism; the civil struggles of 1880 in Argentina; the gradual abandonment of the institutions and educational programs that he himself initiated, and having witnessed the Civil War and the "administrative" end of slavery in the United States.
Without looking for it, because he considered such dissimilar references, he constructed a counterexample that, in the end, is forced to accept the mestizo character of Latin America, although his objective was to denounce the presence of this [ethnic] element. This edition follows the one published by "La cultura argentina" in 1915, with a valuable introduction by José Bengoa and an appendix with correspondence from the author that explains his motivations.