Does καλῶς mean “right” or “well”? This is one of those situations where I would think we hear things differently.
Paul has been arguing for celibacy, the gift that no high school or college student wants. His basic argument is that it is better to remain celibate so as to be able to focus on ministry, but it is only right for those with the spiritual ability to do so. (And all students sigh a sigh of relief.)
Within that context Paul says, “However, the man who stands firm in his resolve is under no compulsion but has control over his desire, and has determined this in his heart to keep her as his virgin, he will do well (καλῶς)” (v 37).
The problem surfaces in the NIV 1984, which says, “this man also does the right thing.” This could seem to mean that the person who chooses celibacy is morally superior to the one who does not.
This is certainly a possible translation of καλῶς. However, in context, it would mean that the person with the gift of celibacy (if I can use that phrase as a shortcut for what Paul is arguing) does the right think for himself. But do you hear it that way?
I think most people hear “right” as morally right. All other translations I check go with “well.”