So, the year 2000? (hp x tr)

'Sure whatever you say'

"In today's class, I wanted to see how much you knew about Light and Dark magic. The differences, their characteristics, anything you know. Yes, mister Abbots?"

"Light magic is defensive and dark magic is offensive."

Professor Peverell didn't reply, just nodded as to say 'Sure whatever you say'

"Yes, mister Weasley?"

"Dark magic is evil and Light magic is good."

"Yes, Mister Potter?"

Now he was interested to know what his grand father thought.

"There's no such thing as Dark or Light magic."

"Are you dumb?" Came an incredulous voice next to him, Miss Prince.

"No. He is not, he's absolutely spot on. Mister Potter is one of the only students in this class who isn't close minded and doesn't just listen to whatever nonsense people say."  Hadrian cut in. "5 Points to Gryffindor, and next time, Miss Prince, it's detention. I want respect in this classroom, it's the only thing I ask."

Every. Single. Student was listening attentively now.

"There is no actual difference between Light and Dark magic. It's all about the user, and their intention. Human Kind, for some reason, feels the need to label everything. I could use Petrificus totalus and bind Mister Longbottom, then make him fly to the sun with a simple Wingardium Leviosa. Both are light spells, but our beloved Longbottom would be fried. It all depends on the intention. Who's still following?"

When only 75 percent of the class' hands went up, he came up with another example.

"Okay, Imagine that "Light magic" was an angel and "Dark magic" was a demon. The Angel is depicted to be good, while the demon is depicted of be evil. But that's not the case, at all. Angels and Demons are only supposed to be the absolutes opposite of each other. Uh- Yes, mister Riddle?"

"I understand this concept but how are you master of the dark arts if there's not a big difference between them?"

"Ah! That is a very very good question, good catch, Riddle. 5 points to Slytherin. There is no difference between light and dark Magic, sure. Magic is Magic. However, Dark and Light Arts are very different. Be very careful which words you're using, similar terms yet very different things. Light Arts art based more off of science and what we know as Alchemy, or Transfiguration. They tend to work closely with muggles and usually come up with more modern spells. I'm not an expert in this field, so if you have questions, you should most probably ask Professor Dumbledore: I would guess that is why "Light Wizards" are now so commonly "Muggle Lovers". Dark arts are based off of rituals, old traditions and spells. That, I can answer your questions on!"

Harry had finished his lecture, he felt quite passionate about these subjects; and clearly the students had seen that, as they had all been taking notes and listening intently.

"With that, today's lesson is finished. My door is open if you need,  but otherwise I'll see you all tomorrow, I hope you have a good day."