His priority did not seem to be to teach them what he knew, but rather to impress upon them that nothing, not even... knowledge, was foolproof.

Sword? Haven't got a sword. That boy has, though. He'll lend you one.

I find that discussing an idea out loud is often the way to kill it stone dead.

Decent people are so easy to manipulate, Potter.

You place too much importance... on the so-called purity of blood! You fail to recognize that it matters not what someone is born, but what they grow to be!

Many prefer not to exercise their imaginations at all. They choose to remain comfortably within the bounds of their own experience, never troubling to wonder how it would feel to have been born other than they are.

I think it's alarming that people believe that success enables one to forget how life felt before. As if one could simply exchange one's values.