That may be my new all time fav quote....beautiful!
The best way to demonstrate that positive rights can't exist is by explaining that in order to forcefully provide a good or service, that right must become a duty for another person who has to provide it, and it is therefore not a right for the provider. Therefore positive rights can only exist for a privileged class. Rights are supposed to be something that exists for all people. Negative rights fulfill this requirement. Negative rights - the right to be free from aggression - can be universalized to all.
Quite well stated Mr. O'Rourke.