"What does it profit, my brethren, if someone says he has faith but does not have works? Can faith save him? If a brother or sister is naked and destitute of daily food, and one of you says to them, "Depart in peace, be warmed and filled," but you do not give them the things which are needed for the body, what does it profit? Thus also faith by itself, if it does not have works, is dead. But someone will say, "You have faith, and I have works." Show me your faith without your works, and I will show you my faith by my works. You believe that there is one God. You do well. Even the demons believe; and tremble! But do you want to know, O foolish man, that faith without works is dead? Was not Abraham our father justified by works when he offered Isaac his son on the altar? Do you see that faith was working together with his works, and by works faith was made perfect? And the Scripture was fulfilled which says, "Abraham believed God, and it was accounted to him for righteousness." And he was called the friend of God. You see then that a man is justified by works, and not by faith only. Likewise, was not Rahab the harlot also justified by works when she received the messengers and sent them out another way? For as the body without the spirit is dead, so faith without works is dead also" (James 2:14-26).
Look at the examples James cites of "works": clothing the naked, feeding the hungry, the obedience of Abraham, the faithfulness of Rahab (note that Rahab's faith is a work: compare James 2:25 with Heb. 11:31). These works that James cites as salvific are the proverbial "good works" so derided by classical Protestantism. He does not cite circumcision and ceremonial laws as examples of works, as did St. Paul; rather, he is emphasizing adherence to the moral law.
St. James' point here is to stress that simple, intellectual adherence to the truths of the Faith is not sufficient for justification; good deeds must follow as well, or else one's faith is in vain. This is the traditional Catholic interpretation of these texts: that while the kind of ceremonial Jewish precepts written against by St. Paul are certainly not salvific or necessary for our salvation, it is absolutely essential to persist in charity and to cooperate with God's grace by doing "good works"; this is, after all, the meaning of our Lord's parable of the talent. Only those who put their master's money (grace) to "work" and reaped a profit were able to enter into their master's happiness. The servant who did nothing was cast out.