He loved and was very impressed how vocal the Professor was and how he explain things so clearly and precisely. Truth be told he didn't really understand what Transfiguration really was till now. Although he did know the essence and fundamental of the said subject before, there were really things that were bothering him about the subject and he was immensely grateful that as their discussion goes by, he learns new things and get to have a different perspective of the subject.

"So Professor, If Gold were to turn into a cat and have its, say, 'nature, and although that cat is a completely another thing and don't look like Gold anymore, she could still retain of who she really is and how she looks like because the essence of her remains?

"The thing that is bothering me, Sir, is what the essence of hers that remains," He started, smiling slightly and with utter curious tone, he continued, "Is it the strands of her hair? The blood that runs through her veins and arteries? Or perhaps, is it the memories and the love she possesses before she's been made a cat that remains?

"Or is it the whole being of her? Her nature. Her nature and the sheer fact that she is a human and whatever she may transformed into, she will still be always a human 'cause she's a born human, destined to be human...

"Is that really is the essence of a person?"

He wasn't really sure 'bout what he was saying but at least, he articulated what he would want to know and all. In hope that he would get a proper and justifiable explanation, he sighed and took a deep breath. Guh, he did forget to breathe while answering.

And he raised his hand once again upon hearing the Professor's question. "Sir, I think Gamp's law says that we can't transfigure a thing, say a quill, into absolutely nothing and vice versa. Albeit you can make a thing vanish, you can't be so assured that it's been completely vanished.. that it's forever gone. And even the vanishing spell transforms a thing into some other thing. Reducto, for example, vanishes things and transforms it into pure powder."