Near the end of the last century, some legal philosophers adapted the so called causal theories of reference to solve internal problems in legal theory. Among those philosophers, Nicos Stavropoulos adjusted Hilary Putnam’s semantic externalism claiming it as a better philosophical view than legal positivism defended by Herbert Hart. According to him, what determines the correct application of a legal rule must be determined by the objects themselves. In that case, what determines the reference of legal terms is an issue (...) to be solved by the best theory developed. However, this is not the case necessarily: Hart’s model can reach to the same conclusions as an externalist adjustment of law. Furthermore, the epistemic criteria required by Putnam to deal with value judgements are also acceptable in a positivist model. This paper presents the central thesis of Putnam’s semantic externalism, with Stavropoulos adaptations to law, and defends that Hart’s approach to deal with legal rules and Putnam’s approach to deal with language rules can converge. (shrink)