More 1 Corinthians 15

1. Peter saw Jesus after his resurrection
   
2. Then the apostles
   
3. Then over 500 other witnesses
   
4. Most of these eyewitnesses were still alive when 1 Corinthians was written
   
5. Then James
   
6. Then "all the apostles"
   
7. How are "all the apostles" different than the previous categories of eyewitnesses, esp. #14 & 15?