Presumption of legal permissibility

A standard principle in the interpretation of Catholic canon law is the principle that restrictive laws are understood narrowly and permissive ones broadly: i.e., in case of ambiguity, we err on the side of freedom. I’ve wondered if this presumption in favor of freedom is just a principle internal to Catholic canon law or if it is part of the concept of law in general. The background for the question is a broadly natural law conception of positive law, on which not every piece of legislation counts as a law, but only those that satisfy the moral-bindingness conditions.

Here is an argument that the presumption for freedom is more general than for Catholic canon law: the presumption for freedom follows from Aquinas’s principle that in order to be binding, a law must be promulgated.

Promulgation means that the law is made available to the reasonable agent. But insofar as a restrictive law is ambiguous, to that extent it has not been made available to the reasonable agent, and hence thus far it has not been promulgated. Thus, ambiguity in a restrictive law yields freedom. What about a permissive law? Well, since positive law is fundamentally restrictive—everything is legally permitted unless it is expressely forbidden—a “permissive law” is really an exception against the background of a specific restrictive law. Thus, one might have a general restrictive law against civilians carrying spears, and later introduce a specific permissive law allowing it when invaders are nearby. In that case, it is reasonable to think of the two laws as forming a single restrictive unit: “Civilians shall not carry spears, unless invaders are nearby.” And then the the ambiguity-yields-freedom principle for restrictive laws implies that in cases of ambiguity in the permissive exception clause, we also have a presumption for freedom.