I'd reframe it to let him know the importance of being responsible for his own education instead of relying on the school. That way he can take advantage of opportunities at school when they're available and when they're not available, you can help. This book Guerrilla Learning was helpful:
http://www.amazon.com/Guerrilla-Learning-Education-Without-School/dp/0471349607
P.S. My kids didn't get this right away but it seems to be sinking in over time.

Last edited by inky; 12/03/09 08:27 AM. Reason: P.S.