"Yes, they're black.... By the madder ones, you mean the raving kind? Those with wild delusions?"
"Those, and others. I was thinking of the quieter sort, who are seldom called mad. Men and women eaten up with suspicion. So that—I think you've never encountered this, but beware of it if you do—so that everything happening within their purview must be bent to the shape of that suspicion; and to hear them talk you'd suppose the whole world was allied in conspiracy against them. I'd guess that such a state of mind is begotten of a most fearful vanity. And what evil is commoner than vanity? Of course that particular sickness of the mind is only one of its fruits. How seldom do you find anyone who hath ever attempted to look on his own life with something like the eye of eternity! But without at least some detachment, vanity is bound to grow."
"As for example the seeming humility of proper Christians?"
"Oh, that, yes—but don't trouble thyself too much about that. It would seem they need it. Well, and there are those madder ones devoured by jealousy, spite, greed, and fears of a hundred kinds, mostly groundless. It's no-way true that all is vanity, but I think you may say that vanity is the source of nearly all the saddest things in human nature. Nay, I think our poor wench with the fits, by comparison with many respectable souls, is quite sane."
"And so what is madness?"
"Do thou tell me, thou who gavest me once a definition of health that serves me still."
"A—a gross exaggeration of some natural activity of the mind? 'Lilies that fester....'"
"I'm pleased I made thee discover the Sonnets. Yes, that might serve.... But the hunger for verifiable knowledge—now there's an activity of the mind, natural I think, but sluggish or nonexistent in most men, and in a few like thee and me, very intense: are we then mad?"
"If such hunger for knowledge became painful or annoying to others, Amadeus, I am sure we would be called mad."
"Mm-yas—thought I'd caught thee, but (as usual) I'm caught instead. So consider—would you say there are any activities of the mind that would not deserve the name of madness if sorely exaggerated?"