“There are no crimes and no criminals in these days. What is the use of having brains in our profession? I know well that I have it in me to make my name famous. No man lives or has ever lived who has brought the same amount of study and of natural talent to the detection of crime which I have done. And what is the result? There is no crime to detect, or, at most, some bungling villainy with a motive so transparent that even a Scotland Yard official can see through it.”

“I shall never do that,' I answered; 'you have brought detection as near an exact science as it ever will be brought in this world.”

“I should prefer that you do not mention my name at all in connection with this case, as I choose to be only associated with those crimes which present some difficulty in their solution.”

“Well, and there is the end of our little drama," I remarked, after we had sat some time smoking in silence. "I fear that it may be the last investigation in which I shall have the chance of studying your methods. Miss Morstan has done me the honour to accept me as a husband in prospective."He gave a most dismal groan.”

“I said that he was my superior in observation and deduction. If the art of the detective began and ended in reasoning from an armchair, my brother would be the greatest criminal agent that ever lived. But he has no ambition and no energy. He will not even go out of his way to verify his own solutions, and would rather be considered wrong than take the trouble to prove himself right.”

“I think there are certain crimes which the law cannot touch, and which therefore, to some extent, justify private revenge.”

“It's a wicked world, and when a clever man turns his brain to crime it is the worst of all.”