“One man's 'magic' is another man's engineering. 'Supernatural' is a null word.”
-Robert A. Heinlein

“Any sufficiently advanced technology is indistinguishable from magic.” (also known as Clarke's Third Law)
-Arthur C. Clarke

“Any sufficiently advanced magic is indistinguishable from technology.”
-Larry Niven

For more information on magic and spells reroute to magic.