captive wild duck from flying away?"

"One wing is clipped."

"Right. Certain of the feathers are trimmed, which throws the duck off
balance every time he tries to fly. He's crippled, right? But if you
clip the _other_ wing, what happens? He's in balance again. He can't
fly as _well_ as he could before his wings were clipped--but he _can_
fly!

"That's what Brownlee's _geas_ does--restore the balance by clipping
the other wing."

His Grace smiled. There was an odd sort of twinkle in his eyes. "Let
me carry your analogy somewhat farther. If the one wing is too
severely clipped, clipping the other won't help. Our duck wouldn't
have enough lift to get off the ground, even if he's balanced.

"Now, a zany who was that badly crippled--?"

I grinned back at him. "Right. It would be so obvious that he would
have been put away very quickly. He would not be just psychopathic,
but completely psychotic--and demonstrably so."

"Then," the Duke said, still pursuing the same track, "the only way
to 'cure' that kind would be to find a method to ... ah ... 'grow the
feathers back', wouldn't it? And where does that put today's
psychotherapy? Providing, of course, that the analogy follows."

"It does," I said. "The real cure that I want to find would do just
that--'grow the feathers back'. And that's beyond the limits of
psychotherapy, too. That's why Dr. Brownlee and his boys want to study
every zany we bring in, whether he can be helped or not. They're
looking for a _cure_, not a stopgap."

"Let me drag that analogy out just a tiny bit more," said His Grace.
"Suppose there is a genetic defect in the duck which makes it
impossible--absolutely impossible--to grow feathers on that wing. Will
your cure work?"

I was very quiet for along time. At least, it seemed long. The
question had occurred to me before, and I didn't even like to think
about it. Now, I had to face it again for a short while.

"Frankly," I said as evenly as I could, "I doubt that anything could
be done. But that's only an opinion. We don't know enough yet to make
any such predictions. It is my hope that some day we'll find a method
of restoring every human being to his or her full potential--but I'm
not at all certain of what the source of that potential is.

"But when we do get our cure," I went on, "then our first move must be
to abolish the _geas_. And I wish that day were coming tomorrow."

* * * * *

There seemed to b