"Perhaps. But I don't quite see."

"The application--to you?"

"To me?"

"Yes, to you, Cresswell. You have been given a strangely perfect nature.
As you say, you seem to have nothing to do with the matter. You have even
been inclined to rebel against your gift. But, take my advice. Cherish
it. Don't play with it, as you have been playing. Remember, if you lose
heaven, the space once filled by heaven will not be left empty."

"Ah! now I see. You think that I--"

"Might swing from a great height to an equally great depth. That has
been my experience--that the man who is once extreme is always extreme,
but not always in the same way. The greatest libertines have made the
greatest ascetics. But, within my own experience, I have known the
reverse process to obtain. And you, if you changed, might carry Addison
with you."

"But then, doctor, you do believe in these manifestations?"

"Not necessarily. But I believe that the minds of men are often very
carefully, very deftly, poised, and that a little push can send them one
way or the other. Have you ever balanced one billiard-ball on the top of
another?"

"Yes."