Paul: An Apostle?

[Guest JeffCR07]

Ok, particularly in juxtaposition with my Augustine question, this one will probably make everyone think im completely ignorant of the faith. I'm really not, and, ironically enough, I'm looking to get a Doctorate in Theology when I finish my undergrad (I'll be a sophomore this year). My question is this: How are the Apostles determined? I know that the 12 were the ones who were the closest to Christ, and his best friends. After Judas' betrayal, he was replaced by another who had been a disciple from the start and had known Jesus. Paul, however, never even saw Christ in person, let alone spoke with and befriended him during his ministry here on earth. What is it about Paul that makes him an Apostle rather than "simply" a disciple (like, say, Steven, who Paul saw die)?

[Laudate_Dominum]

The 12 were specially set apart as Apostles by Christ Himself. St. Paul too was chosen and set apart by Christ Himself (though post-Resurrection) and given a unique mission to be the Apostle to the gentiles. It was not a title given to him by men.