This week's Friday Fallacy post is going to be an example of an ignoratio elenchi or irrelevant conclusion fallacy. Ignoratio elenchi can be used to describe a broad group of logical fallacies all of which possess the characteristic that the conclusion of the logic does not address the issue in question. This specific example of an ignoratio elenchi argument is the argument that whether or not we should be able to eat meat should be determined by our ability to kill the animals ourselves. I have chosen to call this week's fallacy “If I could kill it myself”; although, a more appropriate name for the general fallacy might be “Appeal to personal ability”.
One omnivorous blogger writes:
“I have started to realize (partially due to moving back to Alaska recently) that if I can't look an animal in the face, kill it and butcher it...should I be eating meat at all?
If I can't do it myself, I expose myself as a hypocrite, because I would rather have someone else do the 'yucky stuff' and I get to reap the benefits.”
A second omnivorous blogger seems to have put themselves through quite a bit of trauma trying to kill an animal in order to prove a point.
“I’ve spent a lot of words in recent posts explaining why I need to know where the animals come from that I eat, but standing there in the brutal sun, feeling like the earth was tilting under my feet and hearing a strange roar in my ears I questioned why this was so important. I felt quite as if I may pass out or possibly throw up at any moment, so why subject myself to this? I wish I could explain eloquently but I can’t. I only knew that if I’m going to eat meat, this was something I had to do. If animals can lose their lives for my dinner, I just needed to feel that I paid my own price, that of feeling the pain of taking one’s life.”
This is not a thought process unique to omnivores trying to justify their own actions as this vegan commenter makes clear:
“One big reason I quit eating meat in the first place was because I realized that I myself could never go out and kill another living thing, so why would I be okay with eating something someone else has bludgeoned to death?”
While our ability to kill an animal may speak to our personal squeamishness and, in the second example given above, personal resolve, it says nothing about whether the action is one we ought to do. If the simple fact that people had the ability to do things justified doing them, then we would have no grounds upon which to call any action unethical. Clearly (Modus Tollendo Tollens) our disagreement with this conclusion speaks to the fact that we do not hold this logic to be sound.
Showing posts with label logical fallacy. Show all posts
Showing posts with label logical fallacy. Show all posts
Friday, October 22, 2010
Friday, October 15, 2010
Friday Fallacy – Illicit Minor
If you have not yet read last week's fallacy on the fallacy of the undistributed middle read that first, as this week's post will only make sense in light of that post.
Like the fallacy of the undistributed middle, illicit minor is also a syllogistic fallacy, and the form is fairly similar. The fallacy of the undistributed middle had the form:
All A are B;
All C are B;
Therefore, all C are A.
Illicit minor has the form:
All A are B;
All A are C;
Therefore, all C are B.
For example:
All animal rights activists are vegans;
All animal rights activists are humans;
Therefore, all humans are vegans.
As pleasant as this conclusion is, we clearly have yet to make it true. In a syllogism, the categorical proposition with the term that comes second in the conclusion, in this case, “all animal rights activists are humans,” is called the major premise, and the categorical proposition with the term that comes first in the conclusion, in this case, “all animal rights activists are vegans,” is called the minor premise. This syllogism is a fallacy because the minor term allows some humans to still not be animal rights activists, yet our conclusion tries to draw from the animal rights activist property of humans in order to draw its conclusion. The name illicit minor derives from the fact that the minor premise does not describe all of the individuals who are described as the subject in the conclusion.
It is still possible for syllogisms of this form to have true conclusions. One example might be:
All cats are animals
All cats are mammals
Therefore, all mammals are animals.
This conclusion is technically true, but it cannot be derived from the two premises given. The fact that the conclusion does not necessarily follow from the premises is what makes an argument a fallacy, not that it is necessarily false.
You may have noticed that last week's fallacy was a bit sparse on the examples. That is because most good examples of syllogistic fallacies are actually cases of illicit minor. Remember that things like “I am an animal rights activist” is the syllogistic equivalent of “All 'me' are animal rights activists.” Here are a few examples of illicit minor in action:
The book The China Study cites studies where animals fed diets high in casein developed certain cancers at a much higher rate than those fed other diets. Casein is an animal protein. We cannot conclude from this, as the China Study attempts to do, that all diets high in animal protein will lead to higher rates of those cancers.
Roundup ready crops may contain unsafe levels of pesticide residue. Roundup ready crops are genetically modified. We cannot conclude from this that all genetically modified crops are necessarily unsafe even if Roundup ready ones are.
All of my blog's readers are becoming more skeptical. All of my blog's readers are or are becoming vegan. Sadly, this doesn't mean that all people who are or are becoming vegan are also becoming more skeptical.
Keep fighting the good fight for rights and reason everyone! More fallacies are on their way.
Like the fallacy of the undistributed middle, illicit minor is also a syllogistic fallacy, and the form is fairly similar. The fallacy of the undistributed middle had the form:
All A are B;
All C are B;
Therefore, all C are A.
Illicit minor has the form:
All A are B;
All A are C;
Therefore, all C are B.
For example:
All animal rights activists are vegans;
All animal rights activists are humans;
Therefore, all humans are vegans.
As pleasant as this conclusion is, we clearly have yet to make it true. In a syllogism, the categorical proposition with the term that comes second in the conclusion, in this case, “all animal rights activists are humans,” is called the major premise, and the categorical proposition with the term that comes first in the conclusion, in this case, “all animal rights activists are vegans,” is called the minor premise. This syllogism is a fallacy because the minor term allows some humans to still not be animal rights activists, yet our conclusion tries to draw from the animal rights activist property of humans in order to draw its conclusion. The name illicit minor derives from the fact that the minor premise does not describe all of the individuals who are described as the subject in the conclusion.
It is still possible for syllogisms of this form to have true conclusions. One example might be:
All cats are animals
All cats are mammals
Therefore, all mammals are animals.
This conclusion is technically true, but it cannot be derived from the two premises given. The fact that the conclusion does not necessarily follow from the premises is what makes an argument a fallacy, not that it is necessarily false.
You may have noticed that last week's fallacy was a bit sparse on the examples. That is because most good examples of syllogistic fallacies are actually cases of illicit minor. Remember that things like “I am an animal rights activist” is the syllogistic equivalent of “All 'me' are animal rights activists.” Here are a few examples of illicit minor in action:
The book The China Study cites studies where animals fed diets high in casein developed certain cancers at a much higher rate than those fed other diets. Casein is an animal protein. We cannot conclude from this, as the China Study attempts to do, that all diets high in animal protein will lead to higher rates of those cancers.
Roundup ready crops may contain unsafe levels of pesticide residue. Roundup ready crops are genetically modified. We cannot conclude from this that all genetically modified crops are necessarily unsafe even if Roundup ready ones are.
All of my blog's readers are becoming more skeptical. All of my blog's readers are or are becoming vegan. Sadly, this doesn't mean that all people who are or are becoming vegan are also becoming more skeptical.
Keep fighting the good fight for rights and reason everyone! More fallacies are on their way.
Friday, October 8, 2010
Friday Fallacy – Fallacy of the Undistributed Middle
The fallacy of the undistributed middle is a form of syllogistic fallacy. Syllogisms consist of three categorical propositions, two assumptions and a conclusion, which are statements of the form (all, some,or none) (items in category A) (are or are not) (items in category B). For example, “all dogs are animals,” would be an example of a categorical proposition. If we combine this with the categorical proposition, “all poodles are dogs,” we can conclude from these two assumptions that, “all poodles are animals.” The logic we have used to make this conclusion is known as syllogistic logic. Here is another example:
No vegans eat meat;
Some raw foodists are vegan;
Therefore, some raw foodists do not eat meat.
If we accept that the first two assumptions are true, then it necessarily follows from those assumptions that the conclusion, some raw foodists do not eat meat, is true as well. There are a limited number of forms syllogistic statements can take. All vegans are not people who eat meat, is the same as saying no vegans eat meat, and vice versa, so there are in actuality 4 different forms a categorical proposition can take and a syllogism consists of 3 individual categorical propositions, so there are 4^3 or 256 possible forms a syllogism can take. Not all of these forms result in conclusions that are always true. For example:
Some raw foodists are vegan;
Some meat eaters are raw foodists;
Therefore, some meat eaters are vegan.
While both of the assumptions above are true, the conclusion is clearly false. Up to this point we have kept the three different categories being used in the syllogism in the same order, but the order can move around so long as three different categories are introduced in the two assumptions, the category that repeats does not repeat in the same assumption, and the conclusion incorporates the two categories that had not yet repeated. For example:
All dogs have tails;
I do not have a tail;
Therefore, I am not a dog.
In this case, the categories, dogs, (things that) have tails, and me, appear in a different order, but in this case we still have a syllogism which (if we accept the premises) yields a conclusion which is necessarily true. Changing the order in which the categories appear does change which syllogisms work and which do not.
Syllogistic logic is something you likely do every day without being consciously aware of it. Notice that statements like, “If someone is vegan then they do not eat meat,” means the same thing as, “all vegans are people who do not eat meat.” The fallacy of the undistributed middle is an example of a syllogism that does not work. It takes the form:
All A are B;
All C are B;
Therefore, all C are A.
or
All A are B;
Some C are B;
Therefore, Some C are A.
For example:
All fruitarians are vegan;
I am a vegan;
Therefore, I am a fruitarian.
In this case the two assumptions may both be true, but the conclusion does not necessarily follow from the assumptions (I assure you that I am not a fruitarian). In this instance it is easy to see that the logic is flawed, but when we incorporate this logic into everyday speech it becomes more difficult to see:
If someone is vegetarian then they never eat meat,
Bob never eats meat,
Therefore, Bob is vegetarian.
In this case the conclusion is necessarily true, but the reason why is unclear. When we said, “if someone is a vegetarian then they never eat meat,” we also meant to imply, “if someone never eats meat, then they are a vegetarian.” This extra assumption can then be used to form a valid syllogism. Sometimes when we use the “if” statement it doesn't work this way:
If someone wears fur, then they do not care about animal rights;
Bob does not care about animal rights;
Therefore, Bob wears fur.
The conclusion that Bob wears fur does not necessarily follow from the assumptions because in this case we did not imply that everyone who doesn't care about animal rights also wears fur.
Here is an example were this may come up in reality.
If someone eats too much meat then they are going to be unhealthy. Bob is unhealthy. We cannot immediately assume that Bob is eating too much meat and that is the source of his poor health.
Check out next week's fallacy, illicit minor.
No vegans eat meat;
Some raw foodists are vegan;
Therefore, some raw foodists do not eat meat.
If we accept that the first two assumptions are true, then it necessarily follows from those assumptions that the conclusion, some raw foodists do not eat meat, is true as well. There are a limited number of forms syllogistic statements can take. All vegans are not people who eat meat, is the same as saying no vegans eat meat, and vice versa, so there are in actuality 4 different forms a categorical proposition can take and a syllogism consists of 3 individual categorical propositions, so there are 4^3 or 256 possible forms a syllogism can take. Not all of these forms result in conclusions that are always true. For example:
Some raw foodists are vegan;
Some meat eaters are raw foodists;
Therefore, some meat eaters are vegan.
While both of the assumptions above are true, the conclusion is clearly false. Up to this point we have kept the three different categories being used in the syllogism in the same order, but the order can move around so long as three different categories are introduced in the two assumptions, the category that repeats does not repeat in the same assumption, and the conclusion incorporates the two categories that had not yet repeated. For example:
All dogs have tails;
I do not have a tail;
Therefore, I am not a dog.
In this case, the categories, dogs, (things that) have tails, and me, appear in a different order, but in this case we still have a syllogism which (if we accept the premises) yields a conclusion which is necessarily true. Changing the order in which the categories appear does change which syllogisms work and which do not.
Syllogistic logic is something you likely do every day without being consciously aware of it. Notice that statements like, “If someone is vegan then they do not eat meat,” means the same thing as, “all vegans are people who do not eat meat.” The fallacy of the undistributed middle is an example of a syllogism that does not work. It takes the form:
All A are B;
All C are B;
Therefore, all C are A.
or
All A are B;
Some C are B;
Therefore, Some C are A.
For example:
All fruitarians are vegan;
I am a vegan;
Therefore, I am a fruitarian.
In this case the two assumptions may both be true, but the conclusion does not necessarily follow from the assumptions (I assure you that I am not a fruitarian). In this instance it is easy to see that the logic is flawed, but when we incorporate this logic into everyday speech it becomes more difficult to see:
If someone is vegetarian then they never eat meat,
Bob never eats meat,
Therefore, Bob is vegetarian.
In this case the conclusion is necessarily true, but the reason why is unclear. When we said, “if someone is a vegetarian then they never eat meat,” we also meant to imply, “if someone never eats meat, then they are a vegetarian.” This extra assumption can then be used to form a valid syllogism. Sometimes when we use the “if” statement it doesn't work this way:
If someone wears fur, then they do not care about animal rights;
Bob does not care about animal rights;
Therefore, Bob wears fur.
The conclusion that Bob wears fur does not necessarily follow from the assumptions because in this case we did not imply that everyone who doesn't care about animal rights also wears fur.
Here is an example were this may come up in reality.
If someone eats too much meat then they are going to be unhealthy. Bob is unhealthy. We cannot immediately assume that Bob is eating too much meat and that is the source of his poor health.
Check out next week's fallacy, illicit minor.
Wednesday, October 6, 2010
Why Skeptic?
Why is it important for us as vegans to be good skeptics as well? Carl Sagan, in his book The Demon Haunted World, writes about the process scientists must go through during their Ph.D. oral examinations. “There is much warm and inspired encouragement of apprentice scientists by their mentors. But the poor graduate student at his or her Ph.D. oral exam is subjected to a withering crossfire of questions from the very professors who have the candidate’s future in their grasp. Naturally the students are nervous; who wouldn’t be? True, they’ve prepared for it for years. But they understand that at this critical moment, they have to be able to answer searching questions posed by experts. So in preparing to defend their theses, they must practice a very useful habit of thought: They must anticipate questions; they have to ask: Where in my dissertation is there a weakness that someone else might find? I’d better identify it before they do.”
We vegans may not be preparing for our Ph.D. oral examinations, but as advocates for veganism, we face a similar crossfire of questions. Those who consume animal products and whose worldviews may be challenged by our ideas are not simply going to let go of what they believe because we tell them to. They are going to ask searching, difficult questions and seek out every possible weakness they can that could explain our objections away in a way that seems most reasonable with what they already believe to be true. If we fail to anticipate others' objections we do not risk having our degrees denied, but we do risk losing a potential vegan and further turning their opinion against considering veganism.
What does it mean to be a good skeptic?
A good skeptic recognizes our tendency to seek out evidence that is in line with our desires. As vegans, we most likely want to hear that a vegan diet is healthy. If we are to be good skeptics hearing information that reinforces this hope, particularly from other vegans, should throw up red flags for us. We should require a higher standard of evidence if anything in favor of our hopes and actively seek out any existing evidence in contradiction of the claim, because this is exactly what our critics are going to do.
A good skeptic is also someone who admits uncertainty where it exists and tries to accurately quantify uncertainty based upon the quality of the evidence. This means when evidence is presented for a hypothesis, they will try to find alternate hypotheses that explain that evidence and judge how much more probable or improbable those alternate hypotheses may be, all the while understanding that there may be other explanations that they have not yet thought of. Recently a study came out linking antibodies to a particular viral infection to obesity in children with those antibodies. This was largely reported as “viral infection may be cause of obesity”, yet many other reasonable explanations for this evidence exist. Perhaps parents who allow their children to be obese are also more likely to expose them to certain diseases. Perhaps obesity makes children more prone to certain infections. Perhaps the study just happened to get a strange sample and the results are not representative of the population as a whole. Similarly, suppose we were to hear that vegans have lower rates of lung cancer. Before jumping on the bandwagon and proclaiming that veganism prevents lung cancer, a good skeptic may want to know if vegans are less likely to smoke than the population as a whole.
A good skeptic recognizes fallacies in thinking. We may have a tendency to distrust claims from people or groups that we find untrustworthy, but just because something comes from an untrustworthy source doesn't necessarily mean it is wrong. If we want to claim that they are wrong, we still must make sure that the evidence against their claim actually exists. This is just one of countless examples of fallacious thinking however. Suppose we were to do a study looking at cancer rates among vegans and we find that in our sample we looked over a hundred different types of cancers, and find that for six of them vegans had significantly lower incidences of those cancers at a 95% confidence level. We cannot conclude from this evidence that vegans have lower incidences of those six cancers. This is an example of the Texas sharpshooter fallacy. We have looked at a mass of scattered evidence and then simply picked out those which happened to look like a pattern in our favor. If we wish to actually test whether vegans have lower incidences of those cancers, we must pose our hypothesis beforehand and then get a sample and see how strong the evidence is to support the hypothesis. Keep in mind, if we do not do this, those who currently disagree with us most certainly will, because finding a hole in our thinking will seem much more reasonable to them then having to significantly alter their worldview.
For a list of logical fallacies: http://en.wikipedia.org/wiki/List_of_logical_fallacies
For a toolkit to use as part of being a good skeptic: http://www.youtube.com/watch?v=eUB4j0n2UDU
We vegans may not be preparing for our Ph.D. oral examinations, but as advocates for veganism, we face a similar crossfire of questions. Those who consume animal products and whose worldviews may be challenged by our ideas are not simply going to let go of what they believe because we tell them to. They are going to ask searching, difficult questions and seek out every possible weakness they can that could explain our objections away in a way that seems most reasonable with what they already believe to be true. If we fail to anticipate others' objections we do not risk having our degrees denied, but we do risk losing a potential vegan and further turning their opinion against considering veganism.
What does it mean to be a good skeptic?
A good skeptic recognizes our tendency to seek out evidence that is in line with our desires. As vegans, we most likely want to hear that a vegan diet is healthy. If we are to be good skeptics hearing information that reinforces this hope, particularly from other vegans, should throw up red flags for us. We should require a higher standard of evidence if anything in favor of our hopes and actively seek out any existing evidence in contradiction of the claim, because this is exactly what our critics are going to do.
A good skeptic is also someone who admits uncertainty where it exists and tries to accurately quantify uncertainty based upon the quality of the evidence. This means when evidence is presented for a hypothesis, they will try to find alternate hypotheses that explain that evidence and judge how much more probable or improbable those alternate hypotheses may be, all the while understanding that there may be other explanations that they have not yet thought of. Recently a study came out linking antibodies to a particular viral infection to obesity in children with those antibodies. This was largely reported as “viral infection may be cause of obesity”, yet many other reasonable explanations for this evidence exist. Perhaps parents who allow their children to be obese are also more likely to expose them to certain diseases. Perhaps obesity makes children more prone to certain infections. Perhaps the study just happened to get a strange sample and the results are not representative of the population as a whole. Similarly, suppose we were to hear that vegans have lower rates of lung cancer. Before jumping on the bandwagon and proclaiming that veganism prevents lung cancer, a good skeptic may want to know if vegans are less likely to smoke than the population as a whole.
A good skeptic recognizes fallacies in thinking. We may have a tendency to distrust claims from people or groups that we find untrustworthy, but just because something comes from an untrustworthy source doesn't necessarily mean it is wrong. If we want to claim that they are wrong, we still must make sure that the evidence against their claim actually exists. This is just one of countless examples of fallacious thinking however. Suppose we were to do a study looking at cancer rates among vegans and we find that in our sample we looked over a hundred different types of cancers, and find that for six of them vegans had significantly lower incidences of those cancers at a 95% confidence level. We cannot conclude from this evidence that vegans have lower incidences of those six cancers. This is an example of the Texas sharpshooter fallacy. We have looked at a mass of scattered evidence and then simply picked out those which happened to look like a pattern in our favor. If we wish to actually test whether vegans have lower incidences of those cancers, we must pose our hypothesis beforehand and then get a sample and see how strong the evidence is to support the hypothesis. Keep in mind, if we do not do this, those who currently disagree with us most certainly will, because finding a hole in our thinking will seem much more reasonable to them then having to significantly alter their worldview.
For a list of logical fallacies: http://en.wikipedia.org/wiki/List_of_logical_fallacies
For a toolkit to use as part of being a good skeptic: http://www.youtube.com/watch?v=eUB4j0n2UDU
Friday, May 21, 2010
Hitler was Veg*n!
It often gets brought up that Hitler was a vegetarian and occasionally someone will go so far as to claim Hitler was a vegan (even though the term was only coined in 1944).
The issue itself isn't a particularly large one for vegans. Attempting to use Hitler's diet to make any point about vegetarianism is using the reductio ad Hitlerum logical falacy (really ignoratio elenchi). I've been told that Hitler didn't smoke either and this doesn't bother me in the least as a non-smoker.
Nonetheless, this is an interesting question relating to veganism and skepticism. What was Hitler's diet like? Was Hitler in fact a vegetarian?
On May 30, 1937 the New York Times published an article titled "Where Hitler Dreams and Plans", written by Otto D. Tolischus. In the article Tolischus writes, "During breakfast, which usually consists of milk, bread, oatmeal, honey, and cheese, [Hitler] reads the newspapers, especially his own Voelkische Beobachter."
Hitler's diet certainly was not light on the animal products, but at least for breakfast it appears Hitler tended to stay vegetarian. Tolischus continues, "It is well known that Hitler is a vegetarian and does not drink or smoke. His lunch and dinner consist, therefore, for the most part of soup, eggs, vegetables and mineral water, although he occasionally relishes a slice of ham and relieves the tediousness of his diet with such delicacies as caviar, luscious fruits and similar tidbits."
Hitler certainly considered himself to be vegetarian, as is written here and is repeated by a number of other sources. At the time this article was published, his diet appears to have been low, but not absent of meat, and high in other animal products. He could most appropriately be described by today's language as a flexitarian.
The issue itself isn't a particularly large one for vegans. Attempting to use Hitler's diet to make any point about vegetarianism is using the reductio ad Hitlerum logical falacy (really ignoratio elenchi). I've been told that Hitler didn't smoke either and this doesn't bother me in the least as a non-smoker.
Nonetheless, this is an interesting question relating to veganism and skepticism. What was Hitler's diet like? Was Hitler in fact a vegetarian?
On May 30, 1937 the New York Times published an article titled "Where Hitler Dreams and Plans", written by Otto D. Tolischus. In the article Tolischus writes, "During breakfast, which usually consists of milk, bread, oatmeal, honey, and cheese, [Hitler] reads the newspapers, especially his own Voelkische Beobachter."
Hitler's diet certainly was not light on the animal products, but at least for breakfast it appears Hitler tended to stay vegetarian. Tolischus continues, "It is well known that Hitler is a vegetarian and does not drink or smoke. His lunch and dinner consist, therefore, for the most part of soup, eggs, vegetables and mineral water, although he occasionally relishes a slice of ham and relieves the tediousness of his diet with such delicacies as caviar, luscious fruits and similar tidbits."
Hitler certainly considered himself to be vegetarian, as is written here and is repeated by a number of other sources. At the time this article was published, his diet appears to have been low, but not absent of meat, and high in other animal products. He could most appropriately be described by today's language as a flexitarian.
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