God works even in sinners to draw them to the end by "instructing through the law and aiding by grace." The law is the "precept of the practical reason." As the moral law of nature, it is the participation of the reason in the all-determining "eternal reason"; but since man falls short in his appropriation of this law of reason, there is need of a "divine law"; and since the law applies to many complicated relations, the "practicae dispositiones" of the human law must be laid down.