James spoke of the royal law and here he meant the Ten Commandments since he cited the specific requirement You shall love your neighbor as yourself. In this he parallels Christ and Paul finding in love of neighbor the sum of the Law and its true fulfillment. James affirms that respect of persons is a breach of this royal law and leads to those indulging in it being convicted by the law of transgression. He then affirms the solidarity of the law so that a breach of it in one specific place is a breach of the whole and makes a person guilty of all. This is a far reaching principle that Paul had also indicated when quoting Deuteronomy 27:26 in Galatians 3:10. Cursed is everyone who continues not in all things that are written in the book of the law to do them. Paul indicated it in Romans 7 when he showed that the conviction that he had broken the 10th commandment made him realize that he had broken the whole law. There the importance of mercy is seen as involved in keeping the spirit of the law. James exhorts us to speak and act as those who are to be judged by a law of liberty so that he sets no limit to the range of the Law meaning it covers all aspects of life. In James 4:11 he warns us by implication against speaking against the Law or judging the Law that is to assume the place of judge instead of doer of the law. Efforts should not be in judging someone else and whether they are keeping the law or not. Instead there should be looking inwardly at ourselves to determine whether or not we are doing those things that are required not only in the letter of the law but especially in the spirit of the law. James could not have used such language unless he had a profound conviction of the perfection of the Law. It is the perfection of the Law as a rule of life for the saints redeemed from its condemnation that James considers it. And so we can call it the perfect law of liberty the Royal Law.