This paper discusses a new philosophical perspective for ethnomathematics which articulates Ludwig Wittgenstein's and Michel Foucault's theoretical notions. It is conceived as a theoretical toolbox which allows the analysis of, on the one hand, the mathematical language games of different forms of life and their family resemblances and, on the other hand, the Eurocentric discourses of academic and school mathematics and their effects of truth. Based on fieldwork done in rural forms of life in the south of Brazil, examples of the use of this perspective are presented. The paper analyzes language games of those different forms of life and the school mathematics discipline, highlighting the complex network of learning and powers that makes other mathematics than that known as the mathematics be positioned "in a void" in school curricula.