Abstract. General theory of law (general jurisprudence, allgemeine Rechtslehre) has often claimed to deal with general or universal concepts, i.e., concepts which are deemed to be common to any legal system whatsoever. At any rate, this is the classic determination of such a field of study as provided by John Austin in the nineteenth century—a determination, however, which deserves careful analysis. In what sense, indeed, can one assert that some legal concepts are common to different legal systems? And, above all, in what sense can one assert that some concepts are common to different languages and cultures? My paper sets out to discuss such questions—although, obviously, they are too complicated to be answered in a single paper. The first section reconstructs the Austinian argument for general jurisprudence by placing it in its historical context. The second section tries to apply to legal concepts some suggestions derived from the contemporary debate on conceptual relativism. The third section, returning to the Austinian problem, comes to the following conclusion: Even if conceptual relativism were true and there were no general or universal legal concepts, this would not invalidate in any way the didactic and scientific value of (general) theory of law.