One of my most beloved heroes in literature is Sherlock Holmes. I have loved his stories since I was a boy. I have now had a chance to reread this story and I come away again enchanted. The beginning of this story is a massive treasure trove of fascinating items mostly just under the surface. What went into the production of these few paragraphs provides a fascinating window into the time that they were written and the mind of the author.

First, the beginning of this story immediately shows that it was written in the late 19^th century and you can tell even if you didn’t know who wrote it. The language is formal and has an air of not being recent. People just don’t write fiction this way anymore.

For example, When Dr. Watson admits to his ignorance of the existence of the Diogenes Club, Holmes explains his ignorance by chalking it up to nature of the club and the men who frequent it. He explains “There are many men in London, you know, who, some from shyness, some from misanthropy, have no wish for the company of their fellows. Yet they are not averse to comfortable chairs and the latest periodicals. It is for the convenience of these that the Diogenes Club was started.” Who talks this way anymore!? There is an intellect and formality to it that is lacking in more recent speech. People who would talk this way now would be laughed at to scorn.

Also, the most amazing part of this section of the story was when Holmes and Dr. Watson meet up with Holmes’ brother Mycroft. Holmes is instantly put in an odd place of being a student at the feet of a master. It is not the normal place for Holmes. Usually the author, Sir Arthur Conan Doyle, puts Holmes on display as the master of deductive reasoning especially in the beginning of his stories having Holmes completely read a client without the client doing or saying anything. This is not at all the case in this story however. From a perch in the Diogenes Club Holmes and Mycroft look below into Pall Mall in London and using methods of deductive reasoning completely describe the recent life history of a man walking around below with Mycroft correcting Holmes.

“An old soldier, I perceive," said Sherlock.

"And very recently discharged," remarked the brother.

"Served in India, I see."

"And a non-commissioned officer."

"Royal Artillery, I fancy," said Sherlock.

"And a widower."

"But with a child."

"Children, my dear boy, children."

"Come," said I, laughing, "this is a little too much."

"Surely," answered Holmes, "it is not hard to say that a man with that bearing, expression of authority, and sunbaked skin, is a soldier, is more than a private, and is not long from India."

"That he has not left the service long is shown by his still wearing his ammunition boots, as they are called," observed Mycroft. "He had not the cavalry stride, yet he wore his hat on one side, as is shown by the lighter skin of that side of his brow. His weight is against his being a sapper. He is in the artillery."

Within these lines hides something else that gives us a look into the mind of Doyle himself. This use of deductive method is an amazing ability and the fact that Doyle can use it in his stories suggests that Doyle himself was a master at it. It comes out in his writing. He writes with a precision of a doctor. His creation, Sherlock Holmes, became famous for his use of deductive reasoning in his cases all the while patiently (and at times impatiently) explaining how simple it was with an “Elementary, my dear Watson.” Elementary indeed!

But Mycroft’s and Holmes’ use of deductive reasoning in this story is not, in my mind, what was so amazing about the brilliant detective or his brother. What was so amazing to me was the remarkable speed in which they accomplished the process of deduction. In seconds, they often knew much of someone’s life history merely by looking at him. How was this accomplished? I believe that besides being a master of deductive reasoning Doyle was also a master of inductive reasoning.

Evidence of this is found in the second paragraph of this story. Doyle, narrating as Dr. Watson, writes, “It was after tea on a summer evening, and the conversation, which had roamed in a desultory, spasmodic fashion from golf clubs to the causes of the change in the obliquity of the ecliptic, came round at last to the question of atavism and hereditary aptitudes.” The rhythm of the conversation is not one of deductive reasoning but of inductive reasoning.

I used to think that inductive and deductive reasoning are mutually exclusive. I don’t think so anymore. Effective deductive reasoning is entirely dependent on previous inductive study. Inductive reasoning merely involves the searching out fragments of useful information from pre-studied categories and patterns. Once the bits of information by category are in place then and only then can the process of deduction begin. In order for the categories and patterns to be set in place one has to study things out before.

The whole science of deduction is undermined, however, by the imposition of arbitrary stove-piping or the overspecialization of subject matter. One has to know how the subjects intermingle. How do get from golf clubs to biological atavism and heredity? This is an exceptionally valuable skill and I wish I had it consistently. All the great generals and thinkers throughout history had it. Clausewitz in his book On War calls it coup d'oeil and said that with it you can sense the rhythm of events to such a degree that you can reasonably predict the future. The concept of coup d’oeil is a fascinating one. All the great generals had it. Clausewitz called in the German Überblick des Feldherrn or overview of the commander. In the Princeton translation it is rendered in the French coup d’oeil which literally means “stroke of the eye.” Clausewitz comments:

Und von der anderen Seite ist dieser leichte Überblick des Feldherrn, diese einfache Vorstellungsart, diese Personifizierung des ganzen kriegerischen Handelns so ganz und gar die Seele jeder guten Kriegführung, daß nur bei dieser großartigen Weise sich die Freiheit der Seele denken läßt, die nötig ist, wenn sie über die Ereignisse herrschen und nicht von ihnen überwältigt werden soll. .” (Clausewitz, Carl Von (1989-06-01). Vom Krieg (Achtes Buche: Kriegsplan. Kapitel Einleitung, end of the fifth paragraph). “When all is said and done, it really is the commander’s coup d’oeil (Überblick des Feldherrn), his ability to see things simply, to identify the whole business of war completely with himself, that is the essence of good generalship. Only if the mind works in this comprehensive fashion can it achieve the freedom it needs to dominate events and not be dominated by them.”

That is how Napoleon was able to have such impeccable timing in battle. Dante also described this skill in part of the 23^rd canto of his Paradiso section of the Divine Comedy. “Nel suo profondo vidi che s’interna, legato con amore in un volume, ciò che per l’universo si squaderna: sustanze e accidenti e lor costume quasi conflati insieme, per tal modo che ciò ch’i’ dico è un semplice lume.” “In its depths I saw bound up in one volume the universe within a single notebook: its substance and accident. All its operations and consequences thereof all interfused together in such a manner that all that I speak of is but one single simple light.” (Dante Aligieri: Paradiso Canto XXXIII)

I think of it as a “god's eye” view of a variety of fragments of information from a wide variety of subjects stitched together into a big picture lying on a metaphorical table within the mind. This table is a paradigm. Without a paradigm, none of the fragments make sense and even a rudimentary process of deduction is short circuited. In order for effective deduction to occur, however, one has to be aware of and be able to use multiple paradigms. Holmes and Mycroft had at their disposal multiple paradigms from which they were able to draw in their respective careers. And apparently, so did Sir Arthur Conan Doyle.