"I fear that if the matter is beyond humanity it is certainly beyond me. Yet we must exhaust all natural explanations before we fall back upon such a theory as this."

"Malingering is a subject upon which I have sometimes thought of writing a monograph."

"Three days of absolute fast does not improve one's beauty, Watson."

"I give you my word that for three days I have tasted neither food nor drink until you were good enough to pour me out that glass of water. But it is the tobacco which I find most irksome."

"But I have reasons to suppose that this opinion would be very much more frank and valuable if he imagines that we are alone."

"The theories which I have expressed there, and which appear to you to be so chimerical, are really extremely practical — so practical that I depend upon them for my bread and cheese."

"Before turning to those moral and mental aspects of the matter which present the greatest difficulties, let the inquirer begin by mastering more elementary problems."

"But the Solar System!" I protested. "What the deuce is it to me?" he interrupted impatiently; "you say that we go round the sun. If we went round the moon it would not make a pennyworth of difference to me or to my work."

"I consider that a man's brain originally is like a little empty attic, and you have to stock it with such furniture as you choose. A fool takes in all the lumber of every sort that he comes across, so that the knowledge which might be useful to him gets crowded out, or at best is jumbled up with a lot of other things, so that he has a difficulty in laying his hands upon it. Now the skillful workman is very careful indeed as to what he takes into his brain-attic. He will have nothing but the tools which may help him in doing his work, but of these he has a large assortment, and all in the most perfect order. It is a mistake to think that this little room has elastic walls and can distend to any extent. Depend upon it, there comes a time when for any addition of knowledge, you forget something that you knew before. It is of the highest importance, therefore, not to have useless facts elbowing out the useful ones."

"You have been in Afghanistan, I perceive"

"Nothing could exceed his energy when the working fit was upon him; but now and again a reaction would seize him, and for days on end he would lie upon the sofa in the sitting room, hardly uttering a word or moving a muscle from morning to night."

"Singularity is almost invariably a clue. The more featureless and commonplace a crime is, the more difficult it is to bring it home."

"[Sherlock Holmes quoting:] "There is danger for him who taketh the tiger cub, and danger also for whoso snatches a delusion from a woman.""

"Never trust to general impressions, my boy, but concentrate yourself upon details."

"It has long been an axiom of mine that the little things are infinitely the most important."

"There is nothing so unnatural as the commonplace."

"Life is infinitely stranger than anything which the mind of man could invent. We would not dare to conceive the things which are really mere commonplaces of existence. If we could fly out of that window hand in hand, hover over this great city, gently remove the roofs, and peep in at the queer things which are going on, the strange coincidences, the plannings, the cross-purposes, the wonderful chains of events, working through generations, and leading to the most outre results, it would make all fiction with its conventionalities and foreseen conclusions most stale and unprofitable."

"I hardly looked at his face. His knees were what I wished to see."

"It is quite a three pipe problem, and I beg that you won't speak to me for fifty minutes."

"As a rule, the more bizarre a thing is the less mysterious it proves to be."

"I know, my dear Watson, that you share my love of all that is bizarre and outside the conventions and humdrum routine of everyday life."

"...but none the less you must come round to my view, for otherwise I shall keep on piling fact upon fact on you, until your reason breaks down under them and acknowledges me to be right."

"To Sherlock Holmes she is always the woman. I have seldom heard him mention her under any other name. In his eyes she eclipses and predominates the whole of her sex. It was not that he felt any emotion akin to love for Irene Adler. All emotions, and that one particularly, were abhorrent to his cold, precise but admirably balanced mind. He was, I take it, the most perfect reasoning and observing machine that the world has seen, but as a lover he would have placed himself in a false position. He never spoke of the softer passions, save with a gibe and a sneer. They were admirable things for the observer — excellent for drawing the veil from men's motives and actions. But for the trained reasoner to admit such intrusions into his own delicate and finely adjusted temperament was to introduce a distracting factor which might throw a doubt upon all his mental results. Grit in a sensitive instrument, or a crack in one of his own high-power lenses, would not be more disturbing than a strong emotion in a nature such as his. And yet there was but one woman to him, and that woman was the late Irene Adler, of dubious and questionable memory."

"It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts."

"You see, but you do not observe. The distinction is clear."

"Winwood Reade is good upon the subject," said Holmes. "He remarks that, while the individual man is an insoluble puzzle, in the aggregate he becomes a mathematical certainty. You can, for example, never foretell what any one man will do, but you can say with precision what an average number will be up to. Individuals vary, but percentages remain constant. So says the statistician."

"It is the unofficial force — the Baker Street irregulars."

"What do you think of this, Holmes? Sholto was, on his own confession, with his brother last night. The brother died in a fit, on which Sholto walked off with the treasure? How's that?" "On which the dead man very considerately got up and locked the door on the inside."

"You know my methods. Apply them."

"How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?"

"Holmes," I said in a whisper, "a child has done this horrid thing!"

"I never make exceptions. An exception disproves the rule."

"He smiled gently. "It is of the first importance," he cried, "not to allow your judgment to be biased by personal qualities. A client is to me a mere unit, a factor in a problem. The emotional qualities are antagonistic to clear reasoning. I assure you that the most winning woman I ever knew was hanged for poisoning three little children for their insurance-money, and the most repellent man of my acquaintance is a philanthropist who has spent nearly a quarter of a million upon the London poor.""

"Hence the cocaine. I cannot live without brain-work. What else is there to live for? Stand at the window here. Was ever such a dreary, dismal, unprofitable world? See how the yellow fog swirls down the street and drifts across the dun-coloured houses. What could be more hopelessly prosaic and material? What is the use of having powers, Doctor, when one has no field upon which to exert them? Crime is commonplace, existence is commonplace, and no qualities save those which are commonplace have any function upon earth."

"I never guess. It is a shocking habit — destructive to the logical faculty."

"Eliminate all other factors, and the one which remains must be the truth."

"I have been guilty of several monographs. They are all upon technical subjects. Here, for example, is one 'Upon the Distinction between the Ashes of the Various Tobaccos'. In it I enumerate a hundred and forty forms of cigar, cigarette, and pipe tobacco, with coloured plates illustrating the difference in the ash."

"He possesses two out of the three qualities necessary for the ideal detective. He has the power of observation and that of deduction. He is only wanting in knowledge."

"His ignorance was as remarkable as his knowledge. Of contemporary literature, philosophy and politics he appeared to know nothing. Upon my quoting Thomas Carlyle, he inquired in the naivest way who he might be and what he had done. My surprise reached a climax, however, when I found incidentally that he was ignorant of the Copernican Theory and of the composition of the Solar System. That any civilized being in this nineteenth century should not be aware that the earth traveled round the sun appeared to me to be such an extraordinary fact that I could hardly realize it."

"My mind," he said, "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. I can dispense then with artificial stimulants. But I abhor the dull routine of existence. I crave for mental exaltation. That is why I have chosen my own particular profession, or rather created it, for I am the only one in the world"

"Which is it to-day," I asked, "morphine or cocaine?" He raised his eyes languidly from the old black-letter volume which he had opened. "It is cocaine," he said, "a seven-per-cent solution. Would you care to try it?"

"I had no idea that such individuals exist outside of stories."

"There is no branch of detective science which is so important and so much neglected as the art of tracing footsteps."

"I have already explained to you that what is out of the common is usually a guide rather than a hindrance. In solving a problem of this sort, the grand thing is to be able to reason backward. That is a very useful accomplishment, and a very easy one, but people do not practice it much. In the everyday affairs of life it is more useful to reason forward, and so the other comes to be neglected. There are fifty who can reason synthetically for one who can reason analytically."

"What you do in this world is a matter of no consequence," returned my companion, bitterly. "The question is, what can you make people believe that you have done?"

"When a fact appears to be opposed to a long train of deductions, it invariably proves to be capable of bearing some other interpretation."

"One's ideas must be as broad as Nature if they are to interpret Nature."