missmagpie
For example, I could shield myself walking down a dark alleyway to make myself less noticable. I could also do the same to slip into a pub underage. How can you say that the magic is 'light' or 'dark when I'm essentially using the same technique? Who is anyone else to say that what I'm doing is right or wrong, light or dark? Those terms are entirely subjective.
For example, a dweomer which slays it's target.
Hard to really use the same technique for compassionate ends, except in the rare case where the recipient is in a life of utter agony.
As far as the Terms Light and Dark, they are easy for people to assign in the rather quaint Light=Good=Holy and Dark=Evil=Infernal sorta sense.
I blame some Christians shoddy attempts to reconcile an Omnipotent diety, with an Omnibenevolent one, with a world that is most certainly not omni-benevolent. Basically, a fair chunk of Western Middle Ages thought which ran with epic battles of good versus evil, Light vs Dark. Oh, that, and D&D.
As a Dualist, I see nothing wrong with the classifications...
However, I would have issues with people who aren't ordinarily dualist using such classifications.
In my manner of viewing matters, most magics are of the world, and no more Good or Evil than anything else which walks the Earth.
The exception comes when a dweomer is fashioned with a specific purpose in mind. Just as a neuro-toxin is a tool of destruction and death, made for that specific purpose, so too go magics. And just as I personally hold the creator of such a foul poison culpable for it's use, do I hold a magus who prepares such incantations culpable for their effects.