I have always had an issue with Sherlock Holmes. Not because I dislike the character or anything like that, but because of his misuse of terms.
Holmes frequently claims that he has arrived at his various astounding conclusions via deduction. Yet, it is clear to anyone familiar with types of inferences that deduction plays a relatively minor role in his reasoning. His keen observations and abductive inferences are what play the larger role in his inferences.
Deductive reasoning is when, given a certain set of assumptions, your conclusion must (logically) be true. There is no possible way that it is not true. So, if your assumptions are:
1. P implies Q
2. P
Then you can deductively conclude: Q
So, for example:
If I am sitting, I am not standing
I am sitting
Therefore, I am not standing
Deductive reasoning is very strong - the only way a valid deductive inference can be incorrect is if one of your assumptions is incorrect.
Abductive reasoning is different. You have some thing(s) to explain, and you do so by reasoning about what could have caused those things.
1. Q
2. P implies Q
Therefore, P (maybe)
For example, my friend is late for our scheduled meeting. If the bus was running late, this would cause her to be late. Therefore, it is reasonable to assume the bus is running late. This is an abductive inference. Even if the assumptions are true, it may be the case that the conclusion is false. However, this is still an invaluable reasoning tool which we all use frequently throughout the day.
The other main form of inferential reasoning is inductive reasoning, where you reach a conclusion based on repeated observations. Just like abductive reasoning, an inductive inference is not as airtight as deductive, and can be incorrect
So, let's look at what Holmes does. I will take the example Wikipedia uses.
1. If leather on the side of a shoe is scored by several parallel cuts, it was caused by someone who scraped around the edges of the sole in order to remove crusted mud.
2. If a London doctor's shoes are scraped to remove crusted mud, the person who so scraped them is the doctor's servant girl.
3. If someone cuts a shoe while scraping it to remove encrusted mud, that person is clumsy and careless.
4. If someone's shoes had encrusted mud on them, that person has been very wet lately and has been out in vile weather.
5. Watson's shoes are cut
Therefore, Watson has been out in vile weather and has a clumsy servant girl.
Note that the first 4 premises must not have been deduced - it is possible for any one of them to be false in certain circumstances, and therefore at least part of the justification for them will be inductive or abductive. Yet, given these premises, there is no big surprise about the conclusion. Nearly anyone who is given these premises could come to the conclusion which Holmes comes to. The deductive inference is not the interesting part. This story of how Holmes did this inference is also very questionable. Did his mind really first come up with all of those disjointed premises, and then realize they all fit together in this nice deductive pattern to a specific conclusion? I find it much more likely that Holmes has really done is made the observation of the cut shoes (an observation), and then realized that the best explanation for the cuts in the shoe is a clumsy servant girl scraping mud off of the shoes (he likely abduced that they were cut while scraping mud off his shoes, and knew from an inductive inference that doctors usually have their servant girls scrape the mud off his shoes). He then realized that this implies that Watson has been muddy and that Watson has a clumsy servant girl. The deduction of these conclusions is secondary to the inference to the best explanation (inference to the best explanation is just abductive reasoning) of the shoe cuts.
A second pedantic issue that I have with Holmes' reasoning is when he claims, about possible explanations "When you have eliminated the impossible, whatever remains, however improbable, must be the truth." While I must admit that this is, technically, true, it is very hard to ever know that you have all of the possible explanations, so you never know exactly what "remains". Simply, this never applies to any of Holmes' situations. He never proves that the various crimes he is investigating could not have been caused by aliens, who used their superior technology to plant evidence. This is extremely improbable, but it has not been shown to be impossible. What Holmes' does do, is inference to the best explanation, not the only remaining possible explanation.
Wednesday, December 23, 2009
Tuesday, December 22, 2009
Reasons to be skeptical
I recently came across a book, Joshi's Holistic Detox: 21 days to a healthier slimmer you - for life by Nish Joshi. I am going to use this book as an example of things that should make you skeptical.
Notice that this is a book about diet and nutrition. As such, this is on a subject which there is copious amounts of serious research on. It is, quite simply, a subject we as humans can readily investigate using well established research techniques. Why is this important? Because this is a field in which it is possible to have expertise.
So, of course, the first question is this: Does the author have any expertise in the field he is writing about? Some quick points about this: in various countries, only particular terms are regulated. The title "Registered Dietitian" are protected titles in Canada and the US, meaning that you are only allowed to use the RD title if you actually have the qualifications for it (meaning you must have received an education from a registered college) - just like you can only call yourself an MD if you have gone through medical school. The term nutritionist, on the other hand, is not regulated in many of the provinces in Canada. This means calling yourself a nutritionist is meaningless in the provinces it is unregulated - I could legally pronounce my dog to be a nutritionist. He is unlikely to ever become an RD, though, as he lacks the capacity to read or write.
So, the first test of this book: Does the author have the qualifications relevant to the subject matter? The answer is, I sure don't think so. The only qualifications which the book suggests that the author has is that he has designed some diets which some celebrities have followed. This is probably the biggest reason to be skeptical of a book like this - it is possible to have professional training in this field, and the author simply lacks it. It is possible that he is a wonderful self-taught nutrition guru, but the fact that he has made no effort in getting registered qualifications of this is worrying.
Second test: Do any of the people who endorse this book have the relevant qualifications? Even if the author does have qualifications, if the only people that have anything positive to say about the book are unqualified, it may mean that the author has a very fringe position in the field. On the back of Joshi's book, there are 2 positive comments from actors (Patsy Kensit and Sadie Frost) and then positive comments from popular magazines. Again, Joshi fails this test.
Now, for some general comments on the content of the book: a quick flip to the back shows that it endorses various sorts of quackery: Acupuncture, allergy elimination, etc. On page 21, he suggests his readers drink 2 litres of water a day (this is 8 cups). This is a common misconception, we do not need this much water intake. The entire book is full of huge claims about toxins in our bodies and that doing various things will flush them out, that the water we drink is full of chemicals, yet there are no citations for any of it.
Now, the book does advise some obviously good things - cutting out junk food, drinking less alcohol, avoiding packaged meals, etc. It is hard to fault this sort of advice, and it certainly isn't the case that everything in the book is untrue. However, we have been given no reason to accept the authority of the author, and so the fact that a claim appears in this book lends it no more weight than it already had on its own.
Notice that this is a book about diet and nutrition. As such, this is on a subject which there is copious amounts of serious research on. It is, quite simply, a subject we as humans can readily investigate using well established research techniques. Why is this important? Because this is a field in which it is possible to have expertise.
So, of course, the first question is this: Does the author have any expertise in the field he is writing about? Some quick points about this: in various countries, only particular terms are regulated. The title "Registered Dietitian" are protected titles in Canada and the US, meaning that you are only allowed to use the RD title if you actually have the qualifications for it (meaning you must have received an education from a registered college) - just like you can only call yourself an MD if you have gone through medical school. The term nutritionist, on the other hand, is not regulated in many of the provinces in Canada. This means calling yourself a nutritionist is meaningless in the provinces it is unregulated - I could legally pronounce my dog to be a nutritionist. He is unlikely to ever become an RD, though, as he lacks the capacity to read or write.
So, the first test of this book: Does the author have the qualifications relevant to the subject matter? The answer is, I sure don't think so. The only qualifications which the book suggests that the author has is that he has designed some diets which some celebrities have followed. This is probably the biggest reason to be skeptical of a book like this - it is possible to have professional training in this field, and the author simply lacks it. It is possible that he is a wonderful self-taught nutrition guru, but the fact that he has made no effort in getting registered qualifications of this is worrying.
Second test: Do any of the people who endorse this book have the relevant qualifications? Even if the author does have qualifications, if the only people that have anything positive to say about the book are unqualified, it may mean that the author has a very fringe position in the field. On the back of Joshi's book, there are 2 positive comments from actors (Patsy Kensit and Sadie Frost) and then positive comments from popular magazines. Again, Joshi fails this test.
Now, for some general comments on the content of the book: a quick flip to the back shows that it endorses various sorts of quackery: Acupuncture, allergy elimination, etc. On page 21, he suggests his readers drink 2 litres of water a day (this is 8 cups). This is a common misconception, we do not need this much water intake. The entire book is full of huge claims about toxins in our bodies and that doing various things will flush them out, that the water we drink is full of chemicals, yet there are no citations for any of it.
Now, the book does advise some obviously good things - cutting out junk food, drinking less alcohol, avoiding packaged meals, etc. It is hard to fault this sort of advice, and it certainly isn't the case that everything in the book is untrue. However, we have been given no reason to accept the authority of the author, and so the fact that a claim appears in this book lends it no more weight than it already had on its own.
Saturday, December 19, 2009
What the Bleep?
I just finished watching possibly the strangest docudrama I have ever had the misfortune of seeing, What the Bleep Do We Know!? The movie was even stranger than I thought it would be. I knew that it had all kinds of weird quantum-consciousness-positive-thinking-magic-powers stuff, but I had never heard about all the other weird stuff in it. There is a misuse of quantum physics, psychology, neuroscience, biology, topped off with some wishy-washy spiritualism. Woven through it all is a bizarre story about a deaf girl.
It is hard to construct exactly what the thesis of the film is. I will, to the best of my ability, attempt to outline it. For the first while, every sentence has at least one mention of "quantum physics" in it. It builds up how strange physics is (although they do so in an often very inaccurate way). It makes the weird claim that Native Americans were unable to see Columbus' ships as they approached, because they had no concept of the ships they were in, and this goes to show that what we see is determined by our preconceptions of it (or some such thing). They then claim that the brain has no way of telling the difference between mental images and sensory perceptions (which is simply false - many of the same mechanisms are used in imagination as they are in actual sensory perception, and this is an interesting and hot topic in cognitive science, but just because some of the same mechanisms are used does not mean they are identical), and then therefore our minds can create our perceptions. This is, somehow, tied to the observer effect in quantum physics (in a way that isn't particularly specified). I have no idea how these two are related - on the one hand, the film seems to be claiming that we can change what we perceive, which would supposedly change the universe for us. On the other hand, it seems to be claiming we can change the universe for other people as well (it claims that people meditating can reduce crime), and this is supposedly due to (a misunderstanding of) the observer effect. Regardless, the bottom line is that we can (the film claims) change the universe through thought.
I was prepared for that sort of stuff. However, it goes on to make some other very strange claims. It speculates based on Hebbian Theory (that which fires together, wires together) that we can affect which of our concepts are interconnected, and attempt to disconnect the positive ones from the negative. It goes on to talk about addiction. It is rather odd the way they flip between nerve cells and normal cells, and between nutrients and neurotransmitters - it claims that we can become addicted to emotions because emotions release chemicals the same way drugs do, and as we become more addicted, the number of receptors for each of these chemicals will decrease. These cells with reduced receptors will then replicate, making more cells with fewer receptors, and OMG THIS MEANS THAT IF YOU ARE ADDICTED TO EMOTIONS THEN YOUR CELLS WILL NOT HAVE THE RECEPTORS THEY NEED TO GET NUTRIENTS AND YOU WILL GET OLD AND DIE. Wait, what? Somewhere we went from claims which might be somewhat plausible (some emotions are correllated with certain neurotransmitters, and I am actually uncertain whether feeling an intense emotion for long periods of time may reduce the number of receptors a neuron has - I need to learn more physiological psychology) to claims that are certainly false (this reduction is receptors will somehow affect how all cells, including ones outside the nervous system, uptake nutrients). The biology is so wishy-washy it is hard to say what exactly their misconceptions are.
Speaking of wishy-washy, the film ends with a bunch of very odd wishy-washy spiritualism. There are claims like that "God is the superposition of all the spirit from all things", and "You are a god in the making". One man claims that he creates his day every morning using his magical powers, and does so by asking "the ultimate observer" (what the bleep does that mean?) to affect the quantum field in such a way to make his life better, but to do it in such a way that it is unexpected. This must make things really convenient - if something good happens, he can claim it was his quantum-magic that did it, but he never has to actually predict what will happen.
The storyline woven into the film was possibly the strangest part. At one point the protagonist is at a wedding, and seems able to see the addictions (or something?) of all of the other wedding guests, and seeing how they are controlled by such addictions. This makes it sound coherent, but the way it is presented is just bonkers. It is amusing to watch, anyways.
In the end, What the Bleep Do We Know!? is a heap of random pseudo-science and misconceptions, presented in an incoherent jumble. I'm not sure why it ever became as big as it was.
It is hard to construct exactly what the thesis of the film is. I will, to the best of my ability, attempt to outline it. For the first while, every sentence has at least one mention of "quantum physics" in it. It builds up how strange physics is (although they do so in an often very inaccurate way). It makes the weird claim that Native Americans were unable to see Columbus' ships as they approached, because they had no concept of the ships they were in, and this goes to show that what we see is determined by our preconceptions of it (or some such thing). They then claim that the brain has no way of telling the difference between mental images and sensory perceptions (which is simply false - many of the same mechanisms are used in imagination as they are in actual sensory perception, and this is an interesting and hot topic in cognitive science, but just because some of the same mechanisms are used does not mean they are identical), and then therefore our minds can create our perceptions. This is, somehow, tied to the observer effect in quantum physics (in a way that isn't particularly specified). I have no idea how these two are related - on the one hand, the film seems to be claiming that we can change what we perceive, which would supposedly change the universe for us. On the other hand, it seems to be claiming we can change the universe for other people as well (it claims that people meditating can reduce crime), and this is supposedly due to (a misunderstanding of) the observer effect. Regardless, the bottom line is that we can (the film claims) change the universe through thought.
I was prepared for that sort of stuff. However, it goes on to make some other very strange claims. It speculates based on Hebbian Theory (that which fires together, wires together) that we can affect which of our concepts are interconnected, and attempt to disconnect the positive ones from the negative. It goes on to talk about addiction. It is rather odd the way they flip between nerve cells and normal cells, and between nutrients and neurotransmitters - it claims that we can become addicted to emotions because emotions release chemicals the same way drugs do, and as we become more addicted, the number of receptors for each of these chemicals will decrease. These cells with reduced receptors will then replicate, making more cells with fewer receptors, and OMG THIS MEANS THAT IF YOU ARE ADDICTED TO EMOTIONS THEN YOUR CELLS WILL NOT HAVE THE RECEPTORS THEY NEED TO GET NUTRIENTS AND YOU WILL GET OLD AND DIE. Wait, what? Somewhere we went from claims which might be somewhat plausible (some emotions are correllated with certain neurotransmitters, and I am actually uncertain whether feeling an intense emotion for long periods of time may reduce the number of receptors a neuron has - I need to learn more physiological psychology) to claims that are certainly false (this reduction is receptors will somehow affect how all cells, including ones outside the nervous system, uptake nutrients). The biology is so wishy-washy it is hard to say what exactly their misconceptions are.
Speaking of wishy-washy, the film ends with a bunch of very odd wishy-washy spiritualism. There are claims like that "God is the superposition of all the spirit from all things", and "You are a god in the making". One man claims that he creates his day every morning using his magical powers, and does so by asking "the ultimate observer" (what the bleep does that mean?) to affect the quantum field in such a way to make his life better, but to do it in such a way that it is unexpected. This must make things really convenient - if something good happens, he can claim it was his quantum-magic that did it, but he never has to actually predict what will happen.
The storyline woven into the film was possibly the strangest part. At one point the protagonist is at a wedding, and seems able to see the addictions (or something?) of all of the other wedding guests, and seeing how they are controlled by such addictions. This makes it sound coherent, but the way it is presented is just bonkers. It is amusing to watch, anyways.
In the end, What the Bleep Do We Know!? is a heap of random pseudo-science and misconceptions, presented in an incoherent jumble. I'm not sure why it ever became as big as it was.
Friday, December 18, 2009
Bunch o' Reviews
It's been quite a while since I have actually posted anything here. I figured I would attempt to get back into it, at least for the next while.
I often write reviews of bad Christian apologetics. To break this trend (and show that this isn't all that I read), I am going to do a few quick reviews of some books I have read recently.
The God Part of the Brain by Matthew Alper
I picked this book up expecting a book full of neuroscientific findings about religious belief. I was very disapointed. Much of the book is, instead, talking about the author's journey away from religious belief, and how basic science has undermined much of traditional religion. I ended up just skimming much of this, since it seemed completely irrelevant to the thesis of the book.
When the thesis is finally mentioned, and the book goes on to explain it, I found the basic idea unoriginal. Basically, a predisposition to religious beliefs evolved to lessen the anxiety humans feel about death. It might have been better if more space was devoted to exploring the evidence and the ramifications of this idea, but the book was short as it was and much of the space was wasted on the bits irrelevant to this thesis.
Overall, I can't recommend this book.
Gödel's Proof by Ernest Nagel, James R. Newman, edited and foreword by Douglas R. Hofstadter
The proof to which the title refers to, of course, is his classic proof of the incompleteness of logical systems (for more specific information, you can read about it on wikipedia). This was enormously important for the history of mathematics, extremely interesting as a logical proof, and has been (unfortunately) misused in attempts to prove all sorts of far-reaching philosophical conclusions.
The book itself presents the argument in a very easy to understand way. It gives the overall structure of the proof, without getting too bogged down in details and formality. It's quite readable (or as readable as you could expect, given the subject matter), and does a wonderful job of getting the basic structure of the proof across.
I highly recommend this to any one who is interested in logic or mathematics, especially those who have not had a chance to study Gödel's result before.
Mindfield by Lone Frank
This books talks about how the cognitive sciences, particularly neuroscience, are having an effect on other fields and on everyday life. A very good balance is achieved between depth and breadth of issues. The book looks at a very broad array of topics, but - although I may have been inspired to want to read more about a specific topic - I never felt that something was covered only superficially.
The topics the book talks about are how neuroscience can give us insight on religion, morality, happiness, social interactions, economics, marketing, and lieing. A very interesting read for anyone interested in any one of those topics.
Happiness by Richard Layard
This book was rather interesting. It looked at many scientific findings about happiness - sociological findings about the happiness of different countries through the years, the effects of various things on the happiness of the individual or a whole country, etc. He uses this to put forward some arguments on policy changes which would increase the happiness of a country, and things which affect happiness in our everyday lives.
This is a very thought-provoking book. I have a feeling many hard-core libertarians would have a lot of problems with the arguments put forward, but I would still recommend this book to them and anyone else interested in the science of happiness.
I often write reviews of bad Christian apologetics. To break this trend (and show that this isn't all that I read), I am going to do a few quick reviews of some books I have read recently.
The God Part of the Brain by Matthew Alper
I picked this book up expecting a book full of neuroscientific findings about religious belief. I was very disapointed. Much of the book is, instead, talking about the author's journey away from religious belief, and how basic science has undermined much of traditional religion. I ended up just skimming much of this, since it seemed completely irrelevant to the thesis of the book.
When the thesis is finally mentioned, and the book goes on to explain it, I found the basic idea unoriginal. Basically, a predisposition to religious beliefs evolved to lessen the anxiety humans feel about death. It might have been better if more space was devoted to exploring the evidence and the ramifications of this idea, but the book was short as it was and much of the space was wasted on the bits irrelevant to this thesis.
Overall, I can't recommend this book.
Gödel's Proof by Ernest Nagel, James R. Newman, edited and foreword by Douglas R. Hofstadter
The proof to which the title refers to, of course, is his classic proof of the incompleteness of logical systems (for more specific information, you can read about it on wikipedia). This was enormously important for the history of mathematics, extremely interesting as a logical proof, and has been (unfortunately) misused in attempts to prove all sorts of far-reaching philosophical conclusions.
The book itself presents the argument in a very easy to understand way. It gives the overall structure of the proof, without getting too bogged down in details and formality. It's quite readable (or as readable as you could expect, given the subject matter), and does a wonderful job of getting the basic structure of the proof across.
I highly recommend this to any one who is interested in logic or mathematics, especially those who have not had a chance to study Gödel's result before.
Mindfield by Lone Frank
This books talks about how the cognitive sciences, particularly neuroscience, are having an effect on other fields and on everyday life. A very good balance is achieved between depth and breadth of issues. The book looks at a very broad array of topics, but - although I may have been inspired to want to read more about a specific topic - I never felt that something was covered only superficially.
The topics the book talks about are how neuroscience can give us insight on religion, morality, happiness, social interactions, economics, marketing, and lieing. A very interesting read for anyone interested in any one of those topics.
Happiness by Richard Layard
This book was rather interesting. It looked at many scientific findings about happiness - sociological findings about the happiness of different countries through the years, the effects of various things on the happiness of the individual or a whole country, etc. He uses this to put forward some arguments on policy changes which would increase the happiness of a country, and things which affect happiness in our everyday lives.
This is a very thought-provoking book. I have a feeling many hard-core libertarians would have a lot of problems with the arguments put forward, but I would still recommend this book to them and anyone else interested in the science of happiness.
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