  His explanation, slightly updated: this very large part of our law could reasonably have been different, in the way that every detail of a maternity hospital could have been somewhat different and large portions of the design could have been very different, even though some features (e.g., that the doors and ceilings are more than two feet high) are entailed by the commission to build a town maternity hospital, and every feature has some rational connection with the commission. The kind of rational connection that holds even where the architect has wide freedom to choose amongst indefinitely many alternatives is called by Aquinas a determinatio of principle(s)—a kind of concretization of the general, a particularization yoking the rational necessity of the principle with a freedom (of the law-maker) to choose between alternative concretizations, a freedom which includes even elements of (in a benign sense) arbitrariness.