Chapter 8 - Fallacies

PHI 1101 - Chapter o8 Fallacies Monday, November 18, 2013 - A fallacy is any error in reasoning Five Fallacies of Relevance - Fallacies in this group involve premises that are not relevant to the conclusion they are meant to support Appeal to Ignorance (Ad Ignorantiam) - If we do not know something, then the point is often an important one to observe - The fallacy is based on the assumption that a statement must be true if it cannot be proven false, or vice-versa - The problem arises with the attempts to infer from the fact that we do not know the claims, the conclusion that they are either true or false - Instead of collecting evidence, we jump to conclusion - Different kinds of evidence: does not have to be a “scientific” one 1. We do not know that statement S is true 2. Therefore, statement S is false - Examples: o That we cannot disprove the existence of ghosts, is not enough evidence to say that ghosts exist o The fact that the Bush administration could not prove that Saddam Hussain did not have weapons of mass destruction was insufficient evidence to say that Saddem had them o Not knowing something is not the same as knowing something  Not knowing could just be that you are lacking tools/materials to reason something (meaning it is not “nonexistence”) while knowing something you have evidence/solid proof - “Absence of evidence is not evidence of absence!” – Carl Sagan, Astronomer - If we don’t know that something exists, if doesn’t mean that it doesn’t; it only means we don’t known one way or the other! - Premises (nothing is known about X) -> conclusion( something known about it) - Examples: o Belief in reincarnation is unwanted, since no one can definitely demonstrate that the soul can enter another body and come back on Earth o It’s clear that God doesn’t exist because science hasn’t proved that he does Successful Arguments: - Concluding that my keys are actually not on my desk is a fair conclusion if I had fully looked over my desk. Then we can say that something is not there. - If you believe that it that UN weapons inspectors could completely scour a whole country for WMDs and they did not find them, then we could successfully conclude that Saddam did not have them. - When a thorough investigation into the subject matter is completed we may, indeed, be able to draw that conclusion - There are many different kinds of authorities - Just because someone is knowledgeable in one field does not mean they are necessarily an expert in another field - Arguer cites unqualified authority… jump to conclusion - Examples: o John Lennon was against the Vietnam war. So, it must have been a big mistake.  John Lennon is a singer o Michael Jordan thinks that Nike makes the best shoes. Buy some today.  Michael Jordan should know about good shoes, he’s a professional athlete and advice not be what you need - Caution: there are cases when the appeal to authority is relevant. There are two conditions that allow the use of authority for our arguments: 1. We lack the information and experience and we cannot obtain it directly by ourselves to make a reasonable decision 2. The authority in question is entitled to this status on the matter (ex. Doctors, lawyers, etc.) Appeal to Popularity (Ad Populum) - This fallacy confuses morality with popularity - Because something is normal by no means makes it objectively right - It also confuses epistemological (truth) claims with what Is common or generally accepted (common sense) - Plato vs. Democracy - Majority rules just means that what is popular is made legitimate, legal - But this is independent of whether the popular opinion is actually correct, right, or true - Fallacy plays upon an apparent human desire to be part of groups - Arguer appeals to the audience’s insecurity - Examples: o Thousands of students protested the bombing of Afghanistan. Perhaps you ought to rethink your support of the administration on this.  Although it was terrible, it is not a good argument to say thousands of people supported it o The vast majority of Canadians were against the war in Iraq. How could you suppor ti then?  That is not the way to prove/argue for it Gambler’s Fallacy: - Fallacy confuses particular experience with general, objective, laws - Watchwords: o Due o Ready o Ripe o Immanent, etc - Gambler should refer to general rule, instead Gambler refers to personal experience - Draws the conclusion that his luck is DUE - All based on luck or thought to be based on the law of nature Two Fallacies of Inadequate Evidence - Fallacies in this group are arguments with premises that present relevant but inadequate evidence False Cause: - Post hoc ergo propter hoc – means, “After this, therefore because of this” - Form: A came before B A caused B - Eighteenth-century philosopher David Hume isolated the problem of causation as a problem of induction. Thus, causation can never be proven. o Couldn’t prove the fact that when a rock is thrown, the window will always shatter… But one out of a million times, it won’t - Hume’s arguments can be summarized thus: 1. Only deductive arguments can demonstrate their conclusion 2. Inductive arguments, or arguments from experience, are deductively valid 3. Inductive arguments, or arguments from experience, cannot demonstrate their conclusion - Premises dependent on non-existent causal connection -> conclusion - Examples: o Paul had bacon and eggs and three pancakes for breakfast. Then he took the SAT exam. He scored in the top 20%. I’m so proud of him. That just goes to show you everyone should eat a big meal before an exam! o The Dallas group held a rain dance at the Turtle Creek fountain Sunday night, and the group leader Debra Denton claimed it got results. “It rained, didn’t it?” she asked Monday. o Whenever the team is on a winning streak coach Saunders wears the same time to each game. We won the last three games, so Coach Sanders’ lucky tie must be working!  Examples are all based on superstition - The best defence against a false cause is repeated, uninterrupted events that seem to “cause events” observed many times - Hume called causation nothing more than the experience of “constant conduction” Hasty (Inductive) Generalization: - The sample is hopelessly inadequate, so that the inference from the sample to the population is not reliable - Often the generalization is based on an exceedingly small sample of cases- sometimes only one or two - Simple generalizes too quickly. CF. Stereotyping - Specific cases (not representative) -> generalization -> general rule - Examples: o You should buy a Dell computer. They’re great. I bought one last year, and it has given me nothing but flawless performance. o The French are snobby and rude. Remember those two high-and-mighty guys with really bad manners? They’re French, I rest my case. o Psychology majors are incredibly ignorant about human psychology. Believe me; I know what I’m talking about. My best friend is a psychology major. What an ignoramus!  Stereotyping Four Fallacies of Illegitimate Assumption - Fallacies in this group are tied together by the fact that each invokes some illegitimate assumption False Dilemma (False Alternative): - Involves a failure of imagination, failure to consider one or more real possibilities - Attempts to frame the argument using unacceptable parameters - Fools the reader of listener because it follows a valid argument form- the disjunctive syllogism: Either P or Q -> Unacceptable Narrow premise Not P Q - Either or argument- not given any other option- or presented with an alternative option that is incredibly undesirable - Examples: o New Hampshire state motto: live free or die o If you don’t know Bob Dylan, your knowledge of music is inadequate o American: love it or leave it (written at the U.S.- Mexico border) o We must legalize drugs. We either legalize them or pay a heavy toll is lives and