Who is "James" in Galatians 1:19?

Note:  One more reflection drawn from last Sunday's sermon on Galatians 1:18-24:

"But the other apostles, saw I none, save James the Lord's brother" (Galatians 1:19).

Who is this "James" in v. 19?

Is this James the apostle, the son of Zebedee and physical brother of John?  If so, the use of the term “brother of the Lord” would mean “spiritual brother.”

Is it the apostle known as James the son of Alpheus, who was, says John Brown, “our Lord’s cousin”?  Thus “brother” would refer to their near kinship.  Calvin held this view.

Or, is this James, the elder at Jerusalem, and half-brother of Jesus (cf. Mark 6:3; Jude 1:1)?  Is he called an apostle here not in the sense of being one of the Twelve but in the sense of being one specially “sent out” by God (“apostle” coming from the verb apostello, to send out), in the way that Barnabas (also not one of the twelve) is called an “apostle” in Acts 14:4?  When Paul recounts the resurrection appearances of Jesus he notes that Jesus appeared to Cephas (Peter) and the twelve, then the 500 brothers, and “After that, he was seen of James; then of all the apostles” (1 Cor 15:7).

Again, Paul’s point here is that his knowledge of the pure gospel was not dependent on his visits with Peter and James in Jerusalem but that it was consistent with them.  Paul had harmonious fellowship with the men at Jerusalem.  Contrary to what Paul’s opponents in Galatia were saying, Paul and Peter and James preached the same gospel.

JTR