Particularly in the last few years, I have been developing two study programs in parallel: one directed at gaining an understanding of certain particular forms of working-class formation in the peripheral conditions of a former slave-based colony (which took me back to the second half of the 19th century and the beginning of the 20th); and the other focused on an attempt to understand the current pattern of the class struggle in contemporary capitalist society, which means trying to get a clearer picture of the current profile of the working class, especially in Brazil’s situation, as peripheral as ever. What has made it possible, and to a great extent complementary, for me to develop research programs with such widely separated time frames has been a reflection on the working class founded in the conceptual sphere. From that more strictly theoretical point of view, I have based myself on two considerations that I will endeavor to develop in the course of this article: it is necessary to get beyond the narrower concepts of working class and arrive at a broader concept; and, that effort, in my view, can only be successful if we take up, once more, Marx and Engels’ original discussion of the working class, alongside the best elaborations of historical materialism in the critical tradition produced in the 20th century. In doing so, we should certainly not address them as if they were ready-made responses to the challenges of historical research, but rather a valid set of references which, provided they are duly updated and duly take into account contemporary complexity, will continue to be the best we have available.