However, if you want to use it with a current magic system, you _can_ do that. Nothing in the rules negates the abilities of the normal core spellcasting classes, but it would be kinda like using Star Wars force powers and D&D magic in the same game. It might provide a nifty feel to different cultures who use different styles of magic, but for newbies it might be a little too complicated.
Oh, and Antra, I'm glad you liked it. Russ, do you want to offer people a free copy of our next book if they review Elements?