If you trully see him as a friend you have to help him by letting him go. He is your Intellectual Whore. Send him over to
http://www.intellectualwhores.com - hopefully it will open his eyes.
Otherwise he will never get over you. Letting him go is the only way unfortunatelly; otherwise he will continue to hope that one day you will say yes. He doesn't realize that people can't choose to be attracted, as if was a switch that we can mentally flip.
Perhaps, in a year or so, once he has recovered from his IW status, you can be friends again and this time you will get a genuine friend, not one who does everything in hope of getting in your pants.
It's tough love
Cheers.