@Nep: AFAIK sages aren't necessarily capable of using the same kind(s) of magic that actual mages and other actual spellcaster classes (e.g. priests and their divine magic) can do, if they can even use magic. My conception of a sage is a superintelligent person who deals with books and other written lore, able to decipher and store huge amounts of knowledge far better than anyone else. They're basically walking, living encyclopedias, with the likely possibility of having access to secret lore that could possibly be of magical nature; if they can cast magic, it's either because of dabbling in a spellcaster class on the side, or because the knowledge they amassed includes some spells that only require at most a spoken incantation and some commonly found catalysts (i.e. anyone can theoretically do it, it's just incredibly hard to
know how to do it).