"May" seems a weak word when an untrained mage is as much risk to herself as to others. But what about those who refuse even that--how d'you plan to make learning truly compulsory with the recalcitrant? And if they should take all their training and turn around and harm others, for gain or for spite, will the mages of your school be obligated to bring them to justice?

[A brief noise that's almost a laugh follows.] That's what the law's for--making things black and white. It's up to righteous judges to bring the gray back in where it's warranted.

What if she does? Did she have other options to free the slaves? Stripping someone of her volition, her Maker-given free will, even if it's only temporary--it's evil. Maybe not evil beyond excuse, maybe it's evil the same as killing is evil, sometimes excusable-- But this is why I'm not a judge. [Among many other reasons.]