This article analyses Guattari's and Latour's bodies of work as radical developers of a processual and ontological transdisciplinarity. These works impose a definitive break from the history that, in the 1960s, had drawn upon structuralism in order to oppose philosophy with an epistemological revolution from the perspective of a scientific problematization and first transdisciplinary reconfiguration of the sciences de l'homme. It is shown that the second anti-structuralist transdisciplinarity affirms as its raison dêtre "the necessity to return to Pragmatics", to enact (...) the new significance of the transversal constructions liberated by the rhizomatic monism of a hybrid social ontology. Between Guattari, Latour, and the ecologization they share, a total de-epistemologization and re-ontologization is engaged. It leads to the fall of the 'Ontological Iron Curtain' erected by the philosophical tradition between mind and matter, nature and society. The article concludes by critically addressing the final statements of both Guattari and Latour towards a new aesthetic paradigm and a new diplomacy of institutional forms respectively. (shrink)