by Josef Steiff
We look for intervening cause because we think that there is a fixed rule underlying our observations. The Problem of Induction is that we have no good reason for thinking that such a rule exists. If we were to ask someone watching a billiard game why they feel justified in thinking that the ball will go into a particular pocket, their answer would probably be: because that is where it has gone in the past. But we must then ask, what makes you so sure that the future will follow the same rules as the past? The answer cannot be that it will do so because it has done so in the past. That would be circular reasoning. We would be using our inductive reasoning to prove that our inductive reasoning always works. That would be like saying that someone is honest because they say they would never lie.
When Hume says that no “reasonings a priori” will show us that induction works, he is pointing out that deduction can’t cut it. A priori reasoning is the reasoning we do without having to have any experience of the world. For example, I can understand 2 + 2 = 4 even if I have never seen 2 and 2 put together in the world. That is because I understand the rules of arithmetic. Those rules are such that if I am given a certain set of values then a certain result will necessarily follow. 2 and 2 do not equal 5. In order for the rules of arithmetic to be that certain, they cannot depend on any facts about the world that we need to observe before we add 2 and 2. There are no comparable rules that I am familiar with that govern billiard balls. We need to observe things like the slope of the table, the weight of the balls, and so on. Even with all that information, the geometry that many pool sharks rely upon will not predict with one hundred percent accuracy where the ball will go after it is hit.
A popular argument used in defense of induction is that we can observe regular patterns and therefore we have some sense of the underlying rules. In all my life, I have never seen a billiard ball go unmoved upon contact. The preponderance of evidence seems to go against a billiard ball remaining unmoved. The problem with that kind of argument is revealed by a variation on the thought experiment concocted by the philosopher Nelson Goodman in his book Fact, Fiction, and Forecast. Goodman asks us to imagine a property called “grue” which refers to an object that looks green if it is first observed before a certain date (let’s say 2100) and it will look blue if it is first observed after that date. In 2012, you find an emerald that looks green. How do you know if it is green or grue? Green and grue have the same regular behavior up until a certain point. Grue may seem like an arbitrary property, but is it any different from a radioactive element turning into lead or a butterfly into a caterpillar? If you’re dealing with a pattern that is so complex that we can’t observe it in full, how can you differentiate between two possible explanations of that pattern? The Problem of Induction is that there is no definitive reason to prefer one explanation over the other as all the data you collect (until 2100) will support both explanations. After 2100, you’ll know that when you find a green emerald it will really be green, but when you find a blue emerald you won’t be able to tell if it is blue or grue.
Superficial Tricks
Conan Doyle seemed to be pretty well aware of the Problem of Induction. In a short parody he wrote entitled “How Watson Learned the Trick,” Watson tried to turn the table on Holmes. Watson inducted that Holmes was preoccupied because he had not shaved that morning and that he had begun to engage in stock trading because he made a loud exclamation of interest when looking at the financial page.
It turns out that Watson is totally off the mark. Holmes hadn’t shaved because he had sent his razor to be sharpened, and Holmes was showing interest in the cricket scores which are on the page beside the financial news. Holmes is bemused by Watson’s failure to learn his “superficial trick,” but when it comes down to it, there was nothing wrong with Watson’s failed induction. His method was indistinguishable from Holmes’s. The fact that his conclusion was wrong is not an indictment of his method. After all, scientists arrive at wrong conclusions all the time because induction is not guaranteed to lead you to the right conclusion. This doesn’t mean scientists should abandon using induction.
One well-known attempt to defend the scientific method was proposed by the philosopher Karl Popper. Popper argued that scientists don’t use induction to confirm things; instead they make hypotheses based on experience and test their predictions. If their prediction fails, then the hypothesis is thrown out. If the prediction is successful then that doesn’t make the hypothesis true, it merely shows that it is still a viable option. Popper’s theory is known as falsificationism because it holds that the main task for scientists is to try and falsify theories.
What Popper has done is respond to the Problem of Induction by claiming that science isn’t based in induction. So, he hasn’t dealt with the real Problem. In fact, the Problem of Induction haunts falsificationism because there is usually more than one way to understand a failed experiment. It could show that the hypothesis is false or it could show that our means for testing it was based on faulty assumptions. Once again, we can’t easily decide between two explanations for the results we observed.
The best example of Conan Doyle’s misgivings about taking the science of deduction too seriously can be found in his short story, “The Lost Special.” It also illustrates the problems in deciding between explanations when the evidence is incomplete (as it must always be in a true mystery). The story is a report of a curious incident involving the disappearance of a chartered express train to London—the “special” that was “lost” between two stations and the appearance of the body of the special’s driver. There was no sign of any wreckage and no point at which the train could have been diverted from the tracks, except for seven side lines leading to mines in the area. Four of those side lines had their tracks removed, which left only three possibilities, all of which were eliminated because someone would have noticed the train coming through.
The story excerpts a possible solution offered by an unnamed “amateur reasoned of some celebrity” who is thought by some to be Sherlock Holmes. At the very least, he begins his letter with his famous statement about eliminating the impossible. This amateur reasoner opines that one of the three available lines was manned by a crew that was paid by the culprits to assist in their endeavor. Nevertheless, the fate of the lost special remained unknown until the mastermind behind it confessed. One of the side lines where the tracks had been removed was prepared by laying down the missing rails so that railroad employees in the employ of the mastermind (which did not include the driver) sent the special along this abandoned side line and sent the train speeding into an abandoned mine pit. Once the rails were taken away again there was no evidence of the crime.
The case of the lost special is just another example of how far off one’s inductive reasoning can be because the underlying principles are never known to us. If they were, we would simply use true deduction (like a process of elimination) to arrive at a conclusion that must be true. However, whenever we reason about events in the real world, there is always the possibility of another explanation no matter how outlandish it might seem. Had we never found out the truth, the amateur reasoner’s conclusion would have been just as viable as someone who (unknowingly) gave an account of what actually happened.
The Kindly Whispered “Norbury”
In “The Adventure of the Yellow Face,” Watson begins with a note that reminds us that our faith in Holmes’s powers of reasoning might also be the result of a faulty induction. Watson did not usually write about Holmes’s failures to solve a case, though he says there have been some. One notable exception was the case of Effie Munro, in which Watson reported Holmes’s failure because he knew the actual facts. Effie was a widow from America who had remarried and had begun asking her husband for a sizeable sum of money. She had also begun to make surreptitious visits to a house down the road.
Holmes draws the tentative conclusion that Effie is not really a widow and that her first husband had come to visit her in England. The truth turns out to be far different. Effie had bee
n married to an African-American man and had a child with him. Thinking that a biracial child would not be accepted by her new husband, she had brought the child in secret to live in the nearby cottage. The money she requested was for the child’s upkeep. Holmes is chastened by the failure of his inductions and tells Watson, “If it should ever strike you that I am getting a little overconfident in my powers, or giving less pains to a case than it deserves, kindly whisper ‘Norbury’ in my ear and I shall be infinitely obliged to you” (“The Yellow Face”).
Mycroft’s deeper appreciation for the Problem of Induction keeps him from becoming as overconfident as Holmes. Knowing that there is no way to be certain our inductive inferences will be correct, he’s always on the lookout for the facts that don’t fit. Holmes appreciates the Problem enough to test his theories, but he dismisses the Problem after a certain point, which leads to his overconfidence. And because he becomes overconfident, he does not pay attention to the extra details that would lead him to a better solution.
Mycroft’s appreciation for the Problem of Induction would also explain his disinterest in checking to see if his solutions are correct or in trying to prove his inferences to a jury. Since there is nothing that can guarantee an inductive inference, there is also no way to know when we have found proof that the inference is correct. All the evidence in the world might point to someone’s guilt, but there is no way to be sure that we haven’t missed something. “The Greek Interpreter” ends with just an ambiguity. The two villains flee England with the Greek Interpreter’s sister. A newspaper later reports that they two men have been stabbed to death. The police conclude that they stabbed each other after an argument, but Holmes speculates that they were both killed by the sister as revenge for her brother’s murder. He thinks, if he could just find the Greek girl, he could know for sure. (Of course in the Granada TV series with Jeremy Brett, the interpreter’s sister is a willing accomplice, so she would not have sought revenge for her brother.)
Sherlock Holmes takes a Popperian approach to detective work as he seems to think that what he does is not really induction. Holmes develops a theory based upon the facts and then goes about testing it little by little. In “The Adventure of the Bruce-Partington Plans,” he places an ad in the paper and then goes to see who shows up. Because he tests his theories before he exposes the culprit, it can make it seem as if he had the right answer all along. In some stories, he clearly changes his mind as he eliminates different suspects. Holmes’s tests of his theories demonstrate impressive reasoning as he often recognizes implications and nuances that others have ignored.
But this reasoning almost always relies on knowledge of facts about human nature and the natural world to give it a starting point. At its heart, Sherlock’s method is still about provisional observations. Even his ad relied on the assumption that no one else but the guilty party would show up. There would be no misunderstandings, curiosity seekers or anything else like that. Such a test would also not be very effective in ruling out someone who didn’t show up. There could still be co-conspirators. Mycroft’s superior intellect is not reflected in his ability to find the “right” explanation, it’s in his ability to come up with other explanations that need to be considered and to see when the test of a theory might be compromised by its reliance upon induction. I’m not even sure that Mycroft has some extra special power of percipience that lets him see more alternatives. I think that truly understanding the Problem of Induction causes him to look longer and harder for other possible explanations.
Our Best Bet
Despite his appreciation for the Problem of Induction, Mycroft does not take it to extremes. It seems that Mycroft has embraced another possible response to the Problem of Induction originally proposed by the philosopher Hans Reichenbach. Reichenbach’s defense of induction can be summed up as follows: as long as there is one method that enables us to predict the future, then induction will be at least as reliable as that method, if not more so. If the universe was completely chaotic, then induction would work just as well as any other method (which is not at all). If someone could predict the future through a crystal ball, then the rest of us would use induction to realize that we should start listening to the fortune teller’s prediction.
Reichenbach’s argument is known as a pragmatic justification because it simply argues that induction is our best bet, it doesn’t try to prove that it is independently reliable. Mycroft seems to appreciate that the British government is best served when he uses induction to determine a solution to a problem. At the same time, he knows that he’ll never be able to confirm that every bet was well-placed—so he doesn’t bother.
Unlike Sherlock Holmes’s Popperian attitude, Mycroft does not try and justify induction by pretending it is something other than what it really is: astute observation leading to an educated guess about the underlying pattern. Mycroft’s wisdom is that he knows that the “Problem of Induction” is not simply about incomplete evidence. Sherlock appreciates the problem of false statements or misleading evidence and he knows that if new evidence were to come to light he would have to revise his thesis. What he fails to appreciate is that it’s not clear how incomplete evidence can justify any conclusion.
Most of us are content to appeal to the most plausible explanation, but Sherlock is smart enough to avoid that pitfall. Following his famous dictum, he eliminates every other possible explanation until only one remains. But Mycroft knows that it’s impossible to eliminate all but one explanation. Even if there aren’t an infinite number of explanations for a particular set of clues, there seems to be an almost infinite number of ways in which once could be mistaken when concluding that a particular explanation has been “falsified.” The only thing that really seems to motivate Mycroft to take a risk and act on conclusions arrived at by inductive reasoning is when the fate of England rests upon them.
If we were all more humble about our powers of “deduction,” we could avoid a lot of embarrassing instances where we jumped to the wrong conclusions—especially since most of us lack the superior analytical skills of the Holmes brothers and are much more likely to run afoul of—and be frustrated by—the limits of inductive reasoning.
MUSIC AT STRANGE HOURS OR THAT MIXTURE OF IMAGINATION AND REALITY
Chapter 24
Why Sherlock Holmes Is My Favorite Drug User
Kevin Kilroy
Lazily he sits, in his wing back armchair, the heavy curtains pulled shut on Baker Street. A fire crackling in the deep chamber behind the hearth. He is in his robe and slippers, hair a mess, eyes bewildered—a far-away expression contemplating all he finds within.
On the mahogany table next to him, a vial of cocaine, precisely measured; morphine in another. With his long, white, nervous fingers he adjusts the delicate needle, rolls back his left shirtcuff.
Our existence contains more to be investigated than our senses will deliver, and Sherlock Holmes knows it. Intuition, imagination, daydreams, memories, esoteric knowledge gathered into books—he plunges the syringe into his scarred and pocked forearm. The scarlet thread absorbs the solution, rushing throughout his being.
His face and chest flush with the cocaine, he picks up his violin off the floor, neglecting the bow—to touch and pluck chaotically entices him more. Skillfully he navigates this time devoted to spontaneity and imagination.
Then to his reading. A tome of obscure criminal events which occurred in eighteenth-century Norway.
He lights a candle, skillfully administers another dose, and moves closer towards this communion of body and mind. Sherlock Holmes uses drugs with the intention to explore the intricacies of consciousness, to purposefully sculpt his collection of knowledge, and to grow more attune with the event of being.
And all this amounts to the source of his phenomenological powers. When at the scene of a crime observing intricate details and the hidden lives of objects, we trust he has access to an intelligence far more mysterious than most assume possible.
A Clue Isn’t Helpful to the C
ase until the Detective Notices Its Worth
Simply put, phenomenology is the study of essences. The essence of perception; the essence of consciousness. Phenomenology shares similar concerns with philosophy—reality, knowledge, being—yet it differs in that where philosophy has sought to analyze and explain these issues, phenomenology seeks to describe them.
Even before Plato, philosophers have been trying to articulate what constitutes reality. The pendulum of responses has been weighted heavily, causing swings from one side of the spectrum to the other: either the observer imposes order upon the outside world (subjectivity) or the world imposes order upon the observer (objectivity). Phenomenology, developed by Edmund Husserl in the early 1900s, was the first philosophical study to bridge the two—to say “Ah, one’s experience of the murder weapon is the murder weapon itself compounded by the subject’s understanding of murder weapons!” Both subjective mind and objective world work together to create a being’s reality.
Add this all up and we can say that phenomenology is a branch of study which seeks to describe first-person experience through the understanding that reality is an intercourse between subject and object. Each of us experience the world in our own way, and the world imposes itself upon our experience. What this all means is that reality is an event. That subject and object are both criminal and scene of a crime. That all detectives are phenomenologists.