"Celena's species can't breathe fire. I asked her." As odd as it it seems to say that a dragon couldn't do such a thing. "And this is a polymorph spell, which can't inherit the supernatural abilities of the assumed form. Now if I cast shapechange I would be a dragon in all aspects, including the inherent magical power, but--"

He cut himself off sharply, with a rueful smile. "Sorry. Yes. We can do so. Arcane magic, as opposed to divine magic, essentially draws off of an omnipresent energy field. There are two different ways to manipulate it. Anyone who is born with a connection to the magical field, essentially by having some measure of immortal essence within them, is capable of tapping that field directly, and thereby manipulate it in specific ways to produce given effects, or in other words, to cast spells. That is sorcery. Wizardry, on the other hand, involves learning to tap that same field through study, learning, and discipline."