There's more than one kind of positivism.https://en.wikipedia.org/wiki/Logical_positivism
"Comtean positivism had viewed science as description, whereas the logical positivists posed science as explanation, perhaps to better realize the envisioned unity of science..."
In one of the very few funny moments in philosophy, the Logical Positivists blew themselves up when they proved a unity of science was impossible.
Or did you mean "the theory that laws are to be understood as social rules, valid because they are enacted by authority or derive logically from existing decisions, and that ideal or moral considerations (e.g., that a rule is unjust) should not limit the scope or operation of the law."https://plato.stanford.edu/entries/legal-positivism/