This paper discusses the role of Law and Legal Thinking in Critical Theory with specific reference to the arguments that Michael Hardt and Antonio Negri offer in their book Commonwealth . The core idea is that Critical Theory is no less radical, but much more concrete, when it is performing not only an external, but also an internal critique of the Law. It shows that the role of the law in critical theory emerges as a problem when the latter claims that ‘ there is no outside ’ and that ‘ the legal base of the system structures our lives. ’ It then discusses optimistic and pessimistic strategies to overcome the problem, and argue for a demanding strategy which consist in articulating the external and the internal critique of the law. To make this point, the paper goes back to the epistemic context in which critical attitudes are deployed (the ‘ Conflict of the Faculties ’), describes the four theoretical moves constitutive of the historical moment in which, at the end of the 18th Century, modern law as we know it was conceived of and founded; and sketches the key moments of the history of the internal critique of the law. It then illustrates the demanding strategy with examples taken from the field of Intellectual Property, and concludes that the Law is malleable and open enough to allow the thinking and practicing of radical alternatives from within the legal system and also that alternatives spoken in the language of the law are no less radical, but certainly, more concrete than others.