Quote Originally Posted by PeneloRatsbane View Post
Yuffie makes a comment about how all the materia are to do with battles and magic, and how it must have been awful for the ancients because they must have always been fighting (no wonder they died out) so i figured that Materia had like Ancient knowledge in it, cos it comes from the life stream doesn't it.
Yep, that's basically how it's explained in the game - materia, like some of the the Spheres in FFX, are distilled and condensed spirit energy that's been floating around the Lifestream. That can sometimes include memories or powers of particular individuals who've returned to the planet, such as the Ancients - who were spiritually in tune with the planet, and able to communicate with it and call on its powers. Which is what materia allows a regular person to do, albeit in a more limited way.