There is but one step from the grotesque to the horrible.

The Adventure of the Noble Bachelor

Even the best of us are thrown off some- times.

I have heard, Mr. Holmes, that you can see deeply into the manifold wickedness of the human heart.

My mind rebels at stagnation. Give me problems, give me work, give me the most abstruse cryptogram, or the most intricate analysis, and I am in my own proper atmosphere. But I abhor the dull routine of existence. I crave for mental exaltation.

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.

The grand thing is to be able to reason backwards.