Malling's idea had evidently laid a grip upon Chichester's mind.
"Tell me what the double's existence would be, according to you," he said. "Tell me."
"You imagined the lesson learnt by the man so terrible that he fled away into the night."
"Yes."
"Had he been strong enough to stay—"
"Strong enough!" interposed Chichester. "Better say, had he been obliged to stay."
"Very well. Given that compulsion, in my imagination the double must have learnt a lesson, too. If we can learn by contemplation, can we not, must we not, learn by being contemplated? Life is permeated by reciprocity. I can imagine another sermon growing out of yours of last Sunday."
"Yes, you are right—you are right," said Chichester.
"The double, then, in my imagination, would gradually become uneasy under this secret observation. You described him as, his wife gone, sitting down comfortably to write some account of the hidden doings of his life, as, the writing finished, the diary committed to the drawer and safely locked away, rising up to go to rest with a smile of self-satisfaction. It seemed to me that, given my circumstance of the persistent observation, a few nights later matters would have been very different within that room. The hypocrite is happy, if he is happy at all, when he is convinced that his hypocrisy is successful. Take away that certainty, and he would be invaded by anxiety. Set any one to watch him closely, he would certainly suffer, if he knew it."
"If he knew it! That is the point," said Chichester. "You put the man watching the double in hiding."