Fascinated by the recent scientific progress, even some philosophers today claim that philosophy is dead and that natural sciences (quantum cosmology, cognitive sciences) can answer questions which were once considered a domain of metaphysics: is our universe finite? Do we have free will? etc. The essay tries to problematize this claims by raising a series of questions. First, it is easy to show that modern science itself relies on a series of philosophical propositions. Second, what accounts for the role of science in our world is its link with capitalism. Third, we should distinguish between knowledge and truth: not only philosophy, other discourses (like Marxism or psychoanalysis) also practice a notion of truth which cannot be reduced to knowledge.