Decline in Finnish education based on scores recorded in the latest edition of the International Student Assessment (PISA) program has led experts, including the Finnish Minister of Education, to the hypothesis that discipline matrix flexibility would be one of the causes of it. It is so, because Finland has been adopting a National Discipline Matrix Base for Basic Education since 2014. This discipline matrix is substantiated by competencies focused on developing interdisciplinary projects. The study was guided by post-structural theoretical contributions (Ernesto Laclau and Chantal Mouffe and Jacques Derrida) and moored on the argument that Finnish education quality is reference in effective discipline matrix fulfillment, which is boosted by the idea that disciplinary knowledge would ensure education quality. These discourses are loaded with realistic traces whose disciplinary knowledge is substantiated by academic knowledge, which is understood as epistemologically better than other knowledge forms and endowed with the ability to form identities heading towards a previously established direction. The addressed post-structural contributions support the deconstructive level of realistic meanings given to knowledge; consequently, this process implies erasing the sense of learning and redefining assessment practices, according to which, the scores recorded for large-scale school tests point out students' learning. Furthermore, the success of such learning depends on higher investment in teaching disciplinary knowledge.