The proposed reflection, on the possibilities of understanding legal validity within the limits of law, will concentrate on questioning the frontier(s) between juridicity and ajuridicity, considering the intentional relevance of semiotic approaches, but without searching for a narratively justified exposition of such frontier(s), nor for a constitutive heteronomy of substantially binding morality (or moralities), as the foundational and determinant signification of juridicity. It focuses rather on a reflexive critique of the postmodern “promises of legal semiotics” (Jack Balkin), and, in addition, looks for a metanormative and normative comprehension of the substantially filtered and intersubjectively stated—and axiologically and dialogically constituting—foundation(s) and content(s) of juridicity. Intending to discuss whether autonomous material foundations—rather than meanings(-senses)—of law can actually be (or not) asserted at the present time (A. Castanheira Neves)—in face of the growing plurality and complexity of ways of life, and, therefore, of comprehensions of subjectivity and intersubjectivity.