“From a drop of water, a logician could infer the possibility of an Atlantic or a Niagara without having seen or heard of one or the other. So all life is a great chain, the nature of which is known whenever we are shown a single link of it. Like all other arts, the Science of Deduction and Analysis is one which can only be acquired by long and patient study, nor is life long enough to allow any mortal to attain the highest possible perfection in it. 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. Let him, on meeting a fellow-mortal, learn at a glance to distinguish the history of the man, and the trade or profession to which he belongs. Puerile as such an exercise may seem, it sharpens the faculties of observation, and teaches one where to look and what to look for. By a man’s finger-nails, by his coat-sleeve, by his boots, by his trouser knees, by the callosities of his forefinger and thumb, by his expression, by his shirt-cuffs—by each of these things a man’s calling is plainly revealed. That all united should fail to enlighten the competent inquirer in any case is almost inconceivable.”
—A Study in Scarlet
“It is simplicity itself, so absurdly simple that an explanation is superfluous; and yet it may serve to define the limits of observation and of deduction. Observation tells me that you have a little reddish mold adhering to your instep. Just opposite the Wigmore Street Office they have taken up the pavement and thrown up some earth, which lies in such a way that it is difficult to avoid treading in it in entering. The earth is of this peculiar reddish tint which is found, as far as I know, nowhere else in the neighborhood. So much is observation. The rest is deduction.”
—The Sign of Four
“Jealousy is a strange transformer of characters.”
—The Adventure of the Noble Bachelor
“Never trust to general impressions, my boy, but concentrate yourself upon details.”
—A Case of Identity
“Violence does, in truth, recoil upon the violent and the schemer falls into the pit which he digs for another.”
—The Adventure of the Speckled Band
“The affair seems absurdly trifling, and yet I dare call nothing trivial when I reflect that some of my most classic cases have had the least promising commencement. You will remember, Watson, how the dreadful business of the Abernetty family was first brought to my notice by the depth which the parsley had sunk into the butter upon a hot day.”
—The Adventure of the Six Napoleons
“I can understand. There is a mystery about this which stimulates the imagination; where there is no imagination there is no horror. Have you seen the evening paper?”
—A Study in Scarlet
“What you do in this world is a matter of no consequence. The question is, what can you make people believe that you have done?”
—A Study in Scarlet
“Journeys end in lovers’ meetings.”
—The Adventure of the Empty House
“One’s ideas must be as broad as Nature if they are to interpret Nature.”
—A Study in Scarlet
“Moonshine is a brighter thing than fog.”
—The Boscombe Valley Mystery
“It has long been an axiom of mine that the little things are infinitely the most important.”
—A Case of Identity
“Malingering is a subject upon which I have sometimes thought of writing a monograph.”
—The Adventure of the Dying Detective
“This is Grosvenor mixture at eightpence an ounce. As he might get an excellent smoke for half the price, he has no need to practice economy.”
—The Yellow Face
“Oscillation upon the pavement always means an affaire de coeur.”
—A Case of Identity
“Why, the height of a man, in nine cases out of ten, can be told from the length of his stride. It is a simple calculation enough, though there is no use my boring you with figures. I had this fellow’s stride both on the clay outside and on the dust within. Then I had a way of checking my calculation. When a man writes on a wall, his instinct leads him to write above the level of his own eyes. Now that writing was just over six feet from the ground. It was child’s play.”
—A Study in Scarlet
“You have observed, of course, that the ears are not a pair.”
—The Adventure of the Cardboard Box
“Friend Porlock is evidently scared out of his senses—kindly compare the writing in the note to that upon its envelope, which was done, he tells us, before this ill-omened visit. The one is clear and firm. The other hardly legible.”
—The Valley of Fear
“You may have observed the same wheel-tracks going the other way. But the outward-bound ones were very much deeper—so much so that we can say for a certainty that there was a very considerable weight on the carriage.”
—The Greek Interpreter
“He has been in the habit of lighting his pipe at lamps and gas-jets. You can see that it is quite charred all down one side. Of course a match could not have done that. Why should a man hold a match to the side of his pipe? But you cannot light it at a lamp without getting the bowl charred. And it is all on the right side of the pipe. From that I gather that he is a left-handed man. You hold your own pipe to the lamp and see how naturally you, being right-handed, hold the left side to the flame. You might do it once the other way, but not as a constancy. This has always been held so. Then he has bitten through his amber. It takes a muscular, energetic fellow, and one with a good set of teeth, to do that. But if I am not mistaken I hear him upon the stair, so we shall have something more interesting than his pipe to study.”
—The Yellow Face
“He is a cripple in the sense that he walks with a limp; but in other respects he appears to be a powerful and well-nurtured man. Weakness in one limb is often compensated for by exceptional strength in the others.”
—The Man with the Twisted Lip
“If a herd of buffaloes had passed along, there could not be a greater mess.”
—A Study in Scarlet
“When water is near and a weight is missing it is not a very farfetched supposition that something has been sunk in the water.”
—The Valley of Fear
“Surely my deductions are simplicity itself. It would be difficult to name any articles which afford a finer field for inference than a pair of glasses, especially so remarkable a pair as these. That they belong to a woman I infer from their delicacy, and also, of course, from the last words of the dying man. As to her being a person of refinement and well dressed, they are, as you perceive, handsomely mounted in solid gold, and it is inconceivable that anyone who wore such glasses could be slatternly in other respects. You will find that the clips are too wide for your nose, showing that the lady’s nose was very broad at the base. This sort of nose is usually a short and coarse one, but there is a sufficient number of exceptions to prevent me from being dogmatic or from insisting upon this point in my description. My own face is a narrow one, and yet I find that I cannot get my eyes into the center, nor near the center, of these glasses. Therefore, the lady’s eyes are set very near to the sides of the nose. You will perceive that the glasses are concave and of unusual strength. A lady whose vision has been so extremely contracted all her life is sure to have the physical characteristics of such vision, which are seen in the forehead, the eyelids, and the shoulders.”
—The Adventure of the Golden Pince-Nez
“It was easier to know it than to explain why I know it. If you were asked to prove that two and two made four, you might find some difficulty, and yet you are quite sure of the fact. Even across the street I could see a great blue anchor tattooed on the back of the fellow’s hand. That smacked of the sea. He had a military carriage, however, and regulation side whiskers. There we have the marine. He was a man with some amount of self-importance and a certain air of command. You must have observed the way in which he held his head and swung his cane. A steady, respectable, middle-aged man, too, on the face of him—all facts which led me to believe that he had been a sergeant.”
—A Study in Scarlet
“It is perhaps less suggestive than it might have been, and yet there are a few inferences which are very distinct, and a few others which represent at least a strong balance of probability. That the man was highly intellectual is of course obvious upon the face of it, and also that he was fairly well-to-do within the last three years, although he has now fallen upon evil days. He had foresight, but has less now than formerly, pointing to a moral retrogression, which, when taken with the decline of his fortunes, seems to indicate some evil influence, probably drink, at work upon him. This may account also for the obvious fact that his wife has ceased to love him.
“He has, however, retained some degree of self-respect. He is a man who leads a sedentary life, goes out little, is out of training entirely, is middle-aged, has grizzled hair which he has had cut within the last few days, and which he anoints with lime-cream. These are the more patent facts which are to be deduced from his hat. Also, by the way, that it is extremely improbable that he has gas laid on in his house.”
—The Adventures of the Blue Carbuncle
“Why should I be surprised? I receive an anonymous communication from a quarter which I know to be important, warning me that danger threatens a certain person. Within an hour I learn that this danger has actually materialized and that the person is dead. I am interested; but, as you observe, I am not surprised.”
—The Valley of Fear
“Only one important thing has happened in the last three days, and that is that nothing has happened.”
—The Adventure of the Second Stain
“When a woman thinks that her house is on fire, her instinct is at once to rush to the thing which she values most. It is a perfectly overpowering impulse, and I have more than once taken advantage of it. A married woman grabs at her baby; an unmarried one reaches for her jewel-box.”
—A Scandal in Bohemia
“Having sniffed the dead man’s lips, I detected a slightly sour smell, and I came to the conclusion that he had had poison forced upon him.”
—A Study in Scarlet
“According to my experience it is not possible to reach the platform of a Metropolitan train without exhibiting one’s ticket.”
—The Adventure of the Bruce-Partington Plans
“Now having secured the future, we can afford to be more lenient with the past.”
—The Adventure of the Priory School
“The fish you have tattooed immediately above your right wrist could only have been done in China. I have made a small study of tattoo marks and have even contributed to the literature of the subject. That trick of staining the fishes’ scales of a delicate pink is quite peculiar to China.”
—The Red-Headed League
“I observe from your forefinger that you make your own cigarettes. Have no hesitation in lighting one.”
—The Hound of the Baskervilles
“How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?”
—The Sign of Four
“Exactly, I fancy the yew alley, though not marked under that name, must stretch along this line, with the moor, as you perceive, upon the right of it. This small clump of buildings here is the hamlet of Grimpen, where our friend Dr. Mortimer has his headquarters. Within a radius of five miles there are, as you see, only a very few scattered dwellings. Here is Lafter Hall, which was mentioned in the narrative. There is a house indicated here which may be the residence of the naturalist—Stapleton, if I remember right, was his name. Here are two moorland farmhouses, High Tor and Foulmire. Then fourteen miles away the great convict prison of Princetown. Between and around these scattered points extends the desolate, lifeless moor. This, then, is the stage upon which tragedy has been played, and upon which we may help to play it again.”
—The Hound of the Baskervilles
“You did not know where to look, and so you missed all that was important. I can never bring you to realize the importance of sleeves, the suggestiveness of thumb-nails, or the great issues that may hand from a boot-lace.”
—A Case of Identity
“You have a very handsome stick. By the inscription I observed that you had not had it more than a year. But you have taken some pains to bore the head of it and pour melted lead into the hole so as to make it a formidable weapon. I argued that you would not take such precautions unless you had some danger to fear.”
—The “Gloria Scott”
“If you wish to preserve your incognito, I would suggest that you cease to write your name upon the lining of your hat, or else that you turn the crown towards the person whom you are addressing.”
—The Yellow Face
“You see, but you do not observe. The distinction is clear. For example, you have frequently seen the steps which lead up from the hall to this room.”
—A Scandal in Bohemia
“I’m afraid that all the queen’s horses and all the queen’s men cannot avail in this matter.”
—The Adventure of the Bruce-Partington Plans
“There may be some disinclination on the part of the officials to oblige you. There is so much red tape in these matters. I have no doubt that with a little delicacy and finesse the end may be obtained.”
—The Adventure of the Missing Three-Quarter
“There’s an east wind coming all the same, such a wind as never blew on England yet. It will be cold and bitter, and a good many of us may wither before its blast. But it’s God’s own wind none the less, and a cleaner, better, stronger land will lie in the sunshine when the storm has cleared.”
—His Last Bow
“I wonder how a battery feels when it pours electricity into a non-conductor.”
—The Adventure of the Dying Detective
