LogicDO – The Way of Logic

I copied this article from The New England Skeptical Society: http://www.theness.com/articles.asp?id=38  How to Argue

A guide to examining the premises and logic of arguments – including a list of logical fallacies.

Steven Novella, MD

5/8/2006

Arguing is one of those activities most people do but few people do well. Many do not understand what a logical argument even is or how to do it correctly. Yet arguing is an essential skill of critical thinking. How we argue reflects how we think, how we evaluate our own conclusions, and how we challenge the beliefs of others. Even the very purpose of arguing is often misunderstood. I have arguments almost every day. This does not mean I verbally fight with others on a daily basis, but rather I have discussions that involve either attempting to convince another of a specific conclusion, or resolving differing conclusions on a factual matter. In most of the arguments that I find myself the other person has staked out a position and they defend it jealously, as if they were a high-paid lawyer defending a client. This adversarial approach, however, is not constructive. Rather, the parties of an argument should be trying to find common ground, and then proceed carefully from that common ground to resolve any differences. The beauty of a logical argument is that it is, well… logical. It is, in a way, like mathematics. In math 1+1 must =2. If there is a disagreement about this, it can be resolved objectively and definitively. If two people doing the same math problem come up with different answers, how should they respond? Should they each defend their answer at all costs. Or, should they examine each other’s solution to see if one, or both, might contain an error, and then resolve the error to see what the correct answer is? Likewise, if two people have come to different conclusions about a factual claim, then one or both must be wrong. Both cannot be correct. That means that one or both must have made an error in the arguments they used to come to their conclusions. The two parties should work together to examine their arguments and resolve any errors. Keep in mind, this only works if the arguments are about factual claims, not subjective feelings or value judgments. There is no objective way to resolve a difference of opinion regarding aesthetics, for example. You may prefer Mozart to Beethoven, but there is no way to demonstrate the aesthetic superiority of Mozart over Beethoven with facts or logic. It is very helpful, however, to identify when a conclusion contains an aesthetic opinion or a moral choice. It avoids arguing endlessly over an issue that is inherently irresolvable. An excellent example of this is the abortion debate. Ultimately, all arguments over abortion come down to a personal moral choice: which should have greater value, the mother’s right to make choices regarding her own body, or the unborn fetus’s right not to be killed. All attempts to resolve this objectively have resulted in further arguments that are dependent upon value judgments, for example: at what point at or after conception does an embryo or fetus become a person? Also, how does the fetus’s total biological dependence upon its mother affect their respective rights? For this reason abortion is likely to remain a contentious issue, without a definitive resolution. Structure of a Logical Argument Whether we are consciously aware of it or not, our arguments all follow a certain basic structure. They begin with one or more premises, which are facts that the argument takes for granted as the starting point. Then a principle of logic is applied in order to come to a conclusion. This structure is often illustrated symbolically with the following example: Premise1: If A = B, Premise2: and B = C Logical connection: Then (apply principle of equivalence) Conclusion: A = C In order for a conclusion to be considered valid all the premises of an argument must be true, and the logical connection must be valid. I use the term “valid” here specifically to refer to such conclusions, because a conclusion may still be “true” even if it is not valid. This is because it is possible to use wrong information, or faulty logic to reach a conclusion that happens to be true. An invalid argument does not necessarily prove the conclusion false. Demonstrating that an argument is not valid, however, removes it as support for the truth of the conclusion. Breaking down an argument into its components is a very useful exercise, for it enables us to examine both our own arguments and those of others and critically analyze them for validity. This is an excellent way of sharpening one’s thinking, avoiding biases, and making effective arguments. Examine your Premises As stated above, in order for an argument to be valid all of its premises must be true. Often, different people come to different conclusions because they are starting with different premises. So examining all the premises of each argument is a good place to start. There are three types of potential problems with premises. The first, and most obvious, is that a premise can be wrong. If one argues, for example, that evolutionary theory is false because there are no transitional fossils, that argument is invalid because the premise – no transitional fossils – is false. In fact there are copious transitional fossils. Another type of premise error occurs when one or more premise is an unwarranted assumption. The premise may or may not be true, but it has not been established sufficiently to serve as a premise for an argument. Identifying all the assumptions upon which an argument is dependent is often the most critical step in analyzing an argument. Frequently, different conclusions are arrived at because of differing assumptions. Often people will choose the assumptions that best fit the conclusion they prefer. In fact, psychological experiments show that most people start with conclusions they desire, then reverse engineer arguments to support them – a process called rationalization. One way to resolve the problem of using assumptions as premises is to carefully identify and disclose those assumptions up front. Such arguments are often called “hypothetical,” or prefaced with the statement “Let’s assume for the sake of argument.” Also, if two people examine their arguments and realize they are using different assumptions as premises, then at least they can “agree to disagree.” They will realize that their disagreement cannot be resolved until more information is available to clarify which assumptions are more likely to be correct. The third type of premise difficulty is the most insidious: the hidden premise. I have seen this listed as a logical fallacy – the unstated major premise, but it is more accurate to consider it here. Obviously, if a disagreement is based upon a hidden premise, then the disagreement will be irresolvable. So when coming to an impasse in resolving differences, it is a good idea to go back and see if there are any implied premises that have not been addressed. Let’s go back to the transitional fossil example again. Why is it that scientists believe we have many transitional fossils and evolution deniers (creationists or intelligent design proponents) believe that we do not? This would seem to be a straightforward factual claim easily resolvable by checking the evidence. Sometimes evolution deniers are simply ignorant of the evidence or are being intellectually dishonest. However, the more sophisticated are fully aware of the fossil evidence and use a hidden premise to deny the existence of transitional fossils. When a paleontologist speaks of “transitional” fossils, they are referring to species that occupy a space morphologically between two known species. This may be a common ancestor, in which case the transitional fossil will be more ancient than both descendent species; or it can be temporally between two species, the descendent of one and the ancestor of the other. But in reality we often do not know if the transitional species is an actual ancestor or just closely related to the true ancestor. Because evolution is a bushy process, and not linear, most of the specimens we find will lie on an evolutionary side branch. But if they fill a morphological gap in known species, they provide evidence of an evolutionary connection, and therefore qualify as transitional. For example, archaeopteryx may not be on the direct path to modern birds, but clearly they occupy a space that is transitional between therapod dinosaurs and modern birds and one of their close relatives is a direct ancestor to modern birds. When evolution deniers say there are no transitional fossils their unstated major premise is that they are employing a different definition of transitional than is generally accepted in the scientific community. They typically define transitional as some impossible monster with half-formed and useless structures. Or, they may define transitional as only those fossils for which there is independent proof of being a true ancestor, rather than simply closely related to a direct ancestor – an impossible standard. Logical Fallacies Even when all of the premises of an argument are reliably true, the argument may still be invalid if the logic employed is not legitimate – a so called logical fallacy. The human brain is a marvelous machine with capabilities that, in some ways, still outperform the most powerful of super computers. Our brains, however, do not appear to have evolved specifically for precise logic. There are many common logical pitfalls that our minds tend to fall into, unless we are consciously aware of these pitfalls and make efforts to avoid them. Because, as stated above, there is a tendency to start with desired conclusions and then construct arguments to support them, many people will happily draw upon logical fallacies to make their arguments. In fact, if a conclusion is not true one must either employ a false premise or a logical fallacy in order to construct an argument that leads to that conclusion. Remember, a valid argument cannot lead to a false conclusion. So in order to avoid using logical fallacies to construct invalid arguments, we need to understand how to identify fallacious logic. Below I will list the most common logical fallacies, with examples of each. It is important to note that many claims may contain multiple logical fallacies at once. Also, some types of logic may fit into different types of fallacies simultaneously. After reading many different lists of logical fallacies I have noticed that there is a “lumper vs splitter” difference among them. In other words, some lists may define logical fallacies in broad terms that may contain (lump together) many different specific subtypes. Other lists split the different subtypes into their own fallacies, even though the fallacious logic is essentially the same, or at least very similar. I am going to take a combined approach. I will stick to major types of logical fallacies, and then specifically name subtypes beneath them – those that might be found on other lists as separate entries. Non-Sequitur In Latin this term translates to “doesn’t follow.” This refers to an argument in which the conclusion does not necessarily follow from the premises. In other words, a logical connection is implied where none exists. This is the most basic type of logical fallacy, and in fact many of the fallacies listed below are also non-sequiturs but are an identifiable and common type. Subtype: Magical Thinking Magical thinking is perhaps the most common type of non-sequitur. The logical connection in these fallacious arguments are often a vague magical principle not based upon logic or evidence. For example, Feng Shui proponents might argue that it is better to place your bed in a certain position within your bedroom so that luck will flow into your home. Argument from authority The basic structure of such arguments is as follows: Professor X believes A, Professor X speaks from authority, therefore A is true. Often this argument is implied by emphasizing the many years of experience, or the formal degrees held by the individual making a specific claim. The converse of this argument is sometimes used, that someone does not possess authority, and therefore their claims must be false. (This may also be considered an ad-hominen logical fallacy – see below.) In practice this can be a complex logical fallacy to deal with. It is legitimate to consider the training and experience of an individual when examining their assessment of a particular claim. Also, a consensus of scientific opinion does carry some legitimate authority. But it is still possible for highly educated individuals, and a broad consensus to be wrong – speaking from authority does not make a claim true. This logical fallacy crops up in more subtle ways also. For example, UFO proponents have argued that UFO sightings by airline pilots should be considered valid because pilots are trained observers, are reliable characters, and are trained not to panic in emergencies. In essence, they are arguing that we should trust the pilot’s authority as an eye witness. The argument from authority, or appeal to authority, has many potential subtypes, all of which invest authority in a particular group or situation. In the broadest sense this logical fallacy assumes that because a person or group possesses some positive quality (such as authority), their claims are true. Below are some examples of different types of positive qualities worth specific mention. Subtype: Appeal to Common Belief This fallacy is the argument that a claim must be true because many people believe it. It ignores the possibility, demonstrated frequently throughout history, that the majority can be completely wrong. The popularity of an idea or claim is often based upon features other than logic or evidence. Subtype: Appeal to impending acceptance I consider this to be a subtype to the argument from authority, because it attempts to invoke the authority of future belief and acceptance. Many peudosciences, such as creationism, ESP, and UFOlogy, claim that broad acceptance is right around the corner. This is a logical fallacy (the argument from authority) coupled with an assumed premise (that of future acceptance). Subtype: Appeal to virtue or sincerity This is the argument that a person or group possesses a virtue and therefore their claims must be true. For example, alternative medicine proponents often cite that a particular practitioner is very sincere and caring, and therefore claims for the efficacy of their treatment should be believed. Also, a credulous ghosthunter argued to me that an eyewitness who claimed to have seen someone levitate three feet off their bed should be believe because “why would she lie.” Subtype: Argument from Conspiracy or anti-authority This is the converse of the argument from authority, and basically states that a claim is false because it is held and promoted by an authority. This occurs often in the context that the official government position must be false because it’s the official government position. This is more properly considered a subtype of ad-hominem logical fallacy, arguing that the government must be wrong because they habitually lie or engage in cover-up conspiracies. Appeal to Emotion This fallacy is similar to the argument from authority, but I feel deserves a separate entry. Essentially this is any argument that a claim is true because it causes or is associated with positive emotions, or that its converse is associated with negative emotions. A common use of this fallacy is to justify belief in the existence of god. Many argue that god must exist because belief in god makes life worth living, or at least causes happiness and contentment. Also people might argue that they believe in an afterlife because they cannot deal with the alternative that death is final. Argument from final outcome or consequences Such arguments (also called teleological) are based on a reversal of cause and effect, because they argue that something is caused by the ultimate effect that it has, or purpose that is serves. This argument takes some permutation of the form that if a claim were either true or untrue, then the consequences would either be good or bad, and therefore what is true is what leads to either achieving a good outcome or avoiding a bad outcome. For example, Christian creationists have argued that evolution must be wrong because if it were true it would lead to immorality. Subtype: Argument from Benefit Another common, and perhaps more subtle, form of this logical fallacy is the notion that if someone or some entity benefited from an event they must have caused the event. This fallacy is commonly invoked in the context of the JFK assassination in order to support an alleged conspiracy. The argument is that if someone benefited from the assassination of JFK they must have been involved in a conspiracy to carry out the assassination. Subtype: Appeal to Fear The appeal to fear is an argument from consequences, but in this case the consequences are individually relevant – an outcome to be personally feared. For example, proselytizers often argue that you should accept the claims of their religion for if you reject them you risk eternal damnation. Subtype: Appeal to Flattery Like the appeal to fear, this is a personalized version of the argument from final consequences, this time positive rather than negative. This logical fallacy is the attempt to convince someone of a claim because of implied flattery. For example, alleged psychics may support their claims of psychic abilities by claiming that they sense psychic potential in the person they are trying to convince. Subtype: Appeal to Pity This fallacy attempts to support a claim out of pity, sympathy, or even obligation to some person or group. For example, some proponents of Gulf War Syndrome have argued that we should accept the reality of this syndrome because we owe it to our veterans who fought for us in the Gulf War. Another example is the claim that silicone breast implants cause autoimmune disease, despite all evidence to the contrary. During this debate there were many appeals to pity for the victims of silicone breast implants. This can also be considered the fallacy of assuming the conclusion, because having sympathy for the victims of silicone breast implants assumes they are victims, which is the very matter of debate. Post-hoc ergo propter hoc This is perhaps the most common of logical fallacies. It follows the basic format of A preceded B, therefore A caused B, and therefore assumes cause and effect for two events just because they are temporally related (the Latin translates to “after this, therefore because of this”). This logical fallacy is frequently invoked when defending various forms of alternative medicine – I was sick, I took treatment A, I got better, therefore treatment A made me better. It is possible to have recovered from an illness without any treatment. Keep in mind (as with the correlation and causation fallacy described below) it is possible that A did cause B. The logical fallacy is in assuming causation. It is still valid to argue for causation if there is independent evidence to support a causational relationship over other interpretations, such as coincidence. Confusing correlation with causation This is similar to the post-hoc fallacy in that it assumes cause and effect for two variables simply because they occur together. This fallacy is often used to give a statistical correlation a causal interpretation. For example, during the 1990’s both religious attendance and illegal drug use were on the rise. It would be a fallacy to conclude that therefore, religious attendance causes illegal drug use. It is also possible that drug use leads to an increase in religious attendance, or that both drug use and religious attendance are increased by a third variable, such as an increase in societal unrest, or even just population. It is also possible that both variables are independent of one another, and it is mere coincidence that they are both increasing at the same time. This fallacy, however, has a tendency to be abused, or applied inappropriately, to deny all statistical evidence. In fact this constitutes a logical fallacy in itself, the denial of causation. This abuse takes two basic forms. The first is to deny the significance of correlations that are demonstrated with prospective controlled data, such as would be acquired during a clinical experiment. The problem with assuming cause and effect from mere correlation is not that a causal relationship is impossible; it’s just that there are other variables that must be considered and not ruled out a-priori. A controlled trial, however, by its design attempts to control for as many variables as possible in order to maximize the probability that a positive correlation is in fact due to a causation. Further, even with purely epidemiological, or statistical, evidence it is still possible to build a strong scientific case for a specific cause. The way to do this is to look at multiple independent correlations to see if they all point to the same causal relationship. For example, it was observed that cigarette smoking correlates with getting lung cancer. The tobacco industry, invoking the “correlation is not causation” logical fallacy, argued that this did not prove causation. They offered as an alternate explanation “factor x”, a third variable that causes both smoking and lung cancer. But we can make predictions based upon the smoking causes cancer hypothesis. If this is the correct causal relationship, then duration of smoking should correlate with cancer risk, quitting smoking should decrease cancer risk, smoking unfiltered cigarettes should have a higher cancer risk than filtered cigarettes, etc. If all of these correlations turn out to be true, which they are, then the smoking causes cancer hypothesis is supported above other possible causal relationship and it is not a logical fallacy to conclude from this evidence that smoking probably causes lung cancer. Special pleading, or ad-hoc reasoning This is a subtle fallacy which is often difficult to recognize. In essence, it is the arbitrary introduction of new elements into an argument in order to jerry rig them, or fix them so that they appear valid. A good example of this is the ad-hoc dismissal of negative test results. For example, one might argue that ESP has never been demonstrated under adequate test conditions, therefore ESP is not a genuine phenomenon. Defenders of ESP have attempted to counter this argument by introducing the arbitrary premise that ESP does not work in the presence of skeptics. This fallacy is often taken to ridiculous extremes, and more and more bizarre ad hoc elements are added to explain experimental failures or logical inconsistencies. Tu quoque Tu quoque translates to “you too.” This is an attempt to justify wrong action because someone else also does it (two wrongs make a right). “My evidence may be invalid, but so is yours.” This fallacy is frequently committed by proponents of various alternative medicine modalities, who argue that even though their therapies may lack evidence some mainstream modalities also lack evidence. Ad hominem An ad hominem argument is any that attempts to counter another’s claims or conclusions by attacking the person, rather than addressing the argument itself. Taken broadly, this fallacy can be any argument that a person’s claims is false because of a negative quality possessed by the person. True believers will often commit this fallacy by countering the arguments of skeptics by stating that skeptics are closed minded. Skeptics, on the other hand, may fall into the trap of dismissing the claims of UFO believers, for example, by stating that people who believe in UFO’s are crazy or stupid. Sometimes this fallacy can be more subtle. For example, undesired research results can be dismissed because the researchers have an apparent conflict of interest. While true conflicts are a legitimate concern, the use of even minor potential conflicts to dismiss research finding a-priori is little more than an ad hominem logical fallacy. Subtype – Argument from prior error This form of ad hominem logical fallacy argues that the current claims of a person or group are incorrect because of errors committed in the past. Creationists, for example, often point to fossil frauds, or the discovery of living coelacanth previously thought to be extinct to counter the current evidence for evolution. Ad ignorantum The argument from ignorance basically states that a specific belief is true because we don’t know that it isn’t true. Defenders of extrasensory perception, for example, will often overemphasize how much we do not know about the human brain. It is therefore possible, they argue, that the brain may be capable of transmitting signals at a distance. UFO proponents are probably the most frequent violators of this fallacy. Almost all UFO eyewitness evidence is ultimately an argument from ignorance – lights or objects sighted in the sky are unknown, and therefore they are alien spacecraft. Intelligent design is almost entirely based upon this fallacy. The core argument for intelligent design is that there are biological structures that have not been fully explained by evolutionary theory, therefore a powerful intelligent designer must have created them. Confusing absence of evidence with evidence of absence This fallacy cuts both ways. In other words, one might assume that absence of evidence is a compelling argument against the reality of a claim or phenomenon. On the other hand, however, one might dismiss the absence of evidence as having no significance – as not being evidence of absence. In reality, the absence of evidence can only be properly considered in the context of how likely it is that evidence should exist. You must therefore consider how thoroughly evidence has been looked for, and if the tools and techniques employed are capable of finding evidence. For example, if you dredge the bottom of a sea with a net that has one inch holes in order to survey the life living in that sea, you will likely not come up with any creatures smaller than one inch in size. It would not be logical to then conclude that there are no fish smaller than one inch living in that sea. This fallacy is central to the Bigfoot debate. Believers in Bigfoot claim that the absence of hard evidence of Bigfoot is not evidence that Bigfoot does not exist. Skeptics, however, argue that a population of large mammals living in North America should produce some evidence, such as the occasional corpse. Argument from Personal Incredulity I cannot explain, imagine, or understand this, therefore it cannot be true. However, reality is not limited by our ability to comprehend it, or by our comfort with it. Creationists are fond of arguing, for example, that evolution is false because they cannot imagine the complexity of life resulting from blind natural processes, but that does not mean life did not evolve. Subtype: Appeal to Ridicule This form of the argument from personal incredulity argues that a claim is false because it seems ridiculous. Of course, some claims are ridiculous and it is legitimate to arrive at such a conclusion after careful examination of the logic and evidence. However, it is a fallacy to dismiss a claim a-priori simply by labeling it ridiculous or absurd. Many ideas that initially seemed far-fetched, such as the notion that invisible tiny organisms cause disease, or that space and time are relative and not constant, turned out eventually to be proven scientifically valid. Confusing currently unexplained with unexplainable Because we do not currently have an adequate explanation for a phenomenon does not mean that it is forever unexplainable, or that it therefore defies the laws of nature or requires a paranormal explanation. An example of this is the “God of the Gaps” strategy of creationists that whatever we cannot currently explain is unexplainable and was therefore an act of god. The history of science has taught us, however, that even the most intransigent of natural mysteries may eventually yield to scientific investigation. False Dichotomy This fallacy consists of arbitrarily reducing a set of many possibilities to only two. For example, evolution is not possible, therefore we must have been created (assumes these are the only two possibilities). Actually, this fallacy can apply to any premature reduction in the possible set of explanations for a phenomenon – not necessarily down to only two possibilities. UFO proponents, for example, will often analyze a sighting by saying the object was not a plane, not a balloon, and not celestial object, therefore it was a flying saucer. They are limiting the set of possibilities to a few easily dismissed choices, and the desired choice, while ignoring the many other possibilities. This fallacy can also be used to oversimplify a continuum of variation to two black and white choices. For example, science and pseudoscience are not two discrete entities, but rather the methods and claims of all those who attempt to explain reality fall along a continuum from one extreme to the other. False Continuum This is the idea that because there is no definitive demarcation line between two extremes, that the distinction between the extremes is not real or meaningful: There is a fuzzy line between cults and religion, therefore they are really the same thing. This fallacy is especially important to understand in the context of medicine; most human traits vary according to a Bell curve of variation. “Unhealthy” is often defined as being too far out to one extreme or the other. The false continuum logical fallacy is sometimes used to argue that these extremes are merely part of a continuum of variation, and therefore have no meaning or significance. However, this is like saying that “short” and “tall” have no meaning because human height is a continuum of variation. Blood pressure is a good example. We can meaningfully define high blood pressure because it correlates with increased risk of certain disease, such as heart attacks, even though high blood pressure is at the upper end of a continuum of variation. In part this logical fallacy represents discomfort with the concept of a fuzzy line of demarcation between two extremes. But such fuzzy lines are more the rule than the exception in this complex world. Inconsistency Applying criteria or rules to one belief, claim, argument, or position but not to others. For example, some consumer advocates argue that we need stronger regulation of prescription drugs to ensure their safety and effectiveness, but at the same time argue that medicinal herbs (which are pharmacological agents – drugs) should be sold with no regulation for either safety or effectiveness. The Moving Goalpost A method of denial – arbitrarily moving the criteria for “proof” or acceptance out of range of whatever evidence currently exists. Creationists are most famous for this fallacy. In Darwin’s time they argued that in order for evolution to be true there would need to be a method of inheritance that allowed for new variation to persist and propagate, rather than merely become diluted in the larger population. Mendel’s discovery of “genes” fit the bill. They then argued that if evolution were true there should be many transitional fossils, but no number of transitional fossil discoveries seems to be enough to satisfy them. Intelligent Designers now argue that evolution cannot explain the appearance of biochemical pathways and microscopic structures – but as these pathways and structures are rapidly being explained they simply continue to move the goalpost further and further back. Reductio ad absurdum In formal logic, the reductio ad absurdum is a legitimate argument. It follows the form that if the premises are assumed to be true it necessarily leads to an absurd (false) conclusion and therefore one or more premises must be false. The term is now often used to refer to the abuse of this style of argument, by stretching the logic in order to force an absurd conclusion. For example a UFO enthusiast once argued that if I am skeptical about the existence of alien visitors, I must also be skeptical of the existence of the Great Wall of China, since I have not personally seen either. This is a false reductio ad absurdum because he is ignoring evidence other than personal eyewitness evidence, and also logical inference. In short, being skeptical of UFO’s does not require rejecting the existence of the Great Wall. Slippery Slope This logical fallacy is the argument that a position is not consistent or tenable because accepting the position means that the extreme of the position must also be accepted. But moderate positions do not necessarily lead down the slippery slope to the extreme. There may be legitimate reasons to accept intermediate positions. For example, those, like Thomas Szasz, who believe that mental illness does not exist have argued that if we classify depression as an illness that will lead to governments classifying political protest as a mental illness, because they are both mental states. This slippery slope argument ignores the important differences between a debilitating mood disorder and a political opinion. False Analogy This is any argument that is based upon an analogy that is false because of important differences between the situations being compared. Straw Man This is arguing against a position which you create specifically to be easy to argue against, rather than the position actually held by those who oppose your point of view. Therefore this consists of misrepresenting an opposing view in such a way that it is vulnerable to attack, because, for example, it is based upon flimsy evidence or invalid logic. UFO proponents (and many other true believers) have often dismissed skeptics by saying that they reject anything they cannot see with their own eyes. This is a straw man because scientists accept logical inference as a legitimate method. I have never seen a black hole but I accept their reality because the evidence strongly infers their existence. Tautology A tautology is an argument that utilizes circular reasoning, which means that the conclusion is also its own premise. The structure of such arguments is A=B therefore A=B, although the premise and conclusion might be formulated differently so it is not immediately apparent as such. For example, saying that therapeutic touch works because it manipulates the life force is a tautology because the definition of therapeutic touch is the alleged manipulation (without touching) of the life force. Conclusion The more you practice examining arguments for their premises and logical fallacies, the better you will get. I think you will find it is the best method for resolving differences in factual conclusions. It is also helpful in that it can take away the personal emotional content of an argument; if the focus is on facts and logic, the arguments tend to be less personal. Finally, the most important arguments to examine in this way are your own.