"Then the assassin as he withdraws the stiletto from his victim's breast
is not the same man who plunged it in."

"Obviously not," replied the doctor. "He may be exulting in the deed, or,
more likely, he may be in a reaction of regret. He may be worse, he may
be better. His being better or worse makes it neither more nor less just
to punish him, though it may make it more or less expedient. Justice
demands identity; similarity, however close, will not answer. Though a
mother could not tell her twin sons apart, it would not make it any more
just to punish one for the other's sins."

"Then you don't believe in the punishment of crime?" said Henry.

"Most emphatically I do," replied the doctor; "only I don't believe in
calling it justice or ascribing it a moral significance. The punishment
of criminals is a matter of public policy and expediency, precisely like
measures for the suppression of nuisances or the prevention of epidemics.
It is needful to restrain those who by crime have revealed their
likelihood to commit further crimes, and to furnish by their punishment a
motive to deter others from crime."

"And to deter the criminal himself after his release," added Henry.

"I included him in the word 'others,'" said the doctor. "The man who is
punished is other from the man who did the act, and after punishment he
is still other."

"Really, doctor," observed Henry, "I don't see that a man who fully
believes your theory is in any need of your process for obliterating his
sins. He won't think of blaming himself for them any way."