In the present article, we have demonstrated that it is important to understand the equating of mathematics with ontology in Badiou’s philosophy, taking into account the necessary connection between rational materialism and ontological realism. Only in this way can we truly understand Badiou’s fundamental thesis that thinking and being are the same. Philosophy is not ontology and it is not a true procedure, but a thought that arises by being conditioned with the generic thoughts of all four truth procedures (art, (...) politics, science, and love), which in turn does not mean that it cannot speak in the name of truth and ontology. (shrink)