Snape looked horrified. 'You have kept him alive so that he can die at the right moment?''Don't look shocked, Severus. How many men and women have you watched die?''Lately, only those whom I could not save', said Snape.

Was it possible to feel nostalgic about something that had never happened to him, possible for nostalgia to be taken in by the body as a free pathogen to infect the consciousness with stray sentiments? Perhaps, in his dreams, he had traveled back in time, or even drifted into another dimension of space-time and inhabited the body, experiences, and nostalgia of another. To even envisage so allowed the trauma of those lost moments, though not his own, to draw from him a certain envy for the entity in whose memories he had basked vicariously. . .Perhaps, nostalgia was a microorganism. . .the bacterium that infected. . . Yes. . .maybe he was sick.

Potter is mocked by a faculty member for the idea that there is evil in the world from which even children need to learn to defend themselves by the actual practice of doing so rather than familiarity with theory.

It was important, Dumbledore said, to fight, and fight again, and keep fighting, for only then could evil be kept at bay, though never quite eradicated. . . .

I know [Umbridge] by reputation and I'm sure she's no Death Eater-""She's foul enough to be one...""Yes, but the world isn't split into good people and Death Eaters.

It is impossible to manufacture or imitate love.