The Critical Thinker 006 | Introduction to Fallacies

this is the critical thinker episode six hi everyone and welcome to episode six so the critical thinker podcast I'm your host Kevin de la plante I teach philosophy at Iowa State University and I'm also the creator of the website critical thinking tutorials calm which is where this podcast is hosted I know last episode I said I was going to start a new series on the elements of critical thinking but I'm thinking instead that I'll put off starting that series until next episode I'm reminded that it says in the podcast description in iTunes that I'll be using the podcast to answer a listener or viewer email questions but I realized that I haven't done one of those yet so I thought I'd start our first mailbag feature with this episode I received this question several months ago and I picked it because it provides a perfect opportunity to talk about one of the important components of critical thinking which is understanding fallacies okay here's the question it's from a youtuber who goes by the name piss parroting I think I'm saying that right that's th ESP AR ITA n here's question I received this argument in a debate with a creationist it is a fallacy but I want to know which one I called it a use mention error because I couldn't think of anything else I want to know if there is a better explanation here's the argument a computer was created by an intelligent designer the brain is a computer therefore it had an intelligent designer what do you think so the first question is does this argument demonstrate what's known as a use mention error so one thing we'll have to do is talk about what the use mention fallacy is second question if it doesn't commit the use mention fallacy what kind of fallacy does it commit alright let's get started I want to first talk a bit about this notion of a fallacy so what is a fallacy well I've got a four-part definition for you first and foremost a fallacy is an argument so a single statement all by itself can't be a fallacy an argument is a collection of statements where one of the claims is singled out we call it the conclude and the other statements are called the premises and the premises are intended as offering reasons to believe or accept the conclusion so number one a fallacy is an argument number two a fallacy is a bad argument or at least on reflection it's generally recognized to be a bad argument and by that I mean that it's recognized that the premises do not in fact give good reasons to accept the conclusion number three what makes the argument bad is that it has certain generic or general features that are responsible for why it's bad so a fallacy describes a type or class or category of arguments that all have this generic feature in common so we can talk about a given argument as an instance of this generic fallacy type and here's the fourth part of my four part definition fallacies are often or can be mistaken for good arguments if an arguing form is so obviously transparently bad that no one would ever be fooled by it then there wouldn't be much reason to call it a fallacy what motivates the whole business of classifying and analyzing fallacies and why they're always taught in critical thinking classes is that they often are successful at persuading people to accept a conclusion so we have to train people to look for them and recognize them okay that's my four part definition of a fallacy it's worth noting here that while all fallacies are bad arguments not all bad arguments count as fallacies because not all about arguments satisfy all four of these conditions but let's leave that point aside and get back to our question here's a reconstruction of the argument that we're being asked to consider premise 1 computers are products of intelligent design premise 2 the human brain is a computer conclusion the human brain is a product of intelligent design so this is intended as an argument against any naturalistic or evolutionary account of the origins of the human brain now in looking at this argument I want to point out that superficially the logic works just fine it looks like an argument of the form all a or B X is an a therefore X is a B which is what logicians call a valid argument form this is one of the reasons why the argument may be initially persuasive because it looks like an argument with impeccable logical form the other reason why the argument may be initially persuasive is because for many people both that the premises are plausible premise one says that all computers are products of intelligent design that seems right we design and build computers right nature doesn't just assemble them they didn't evolve a natural selection right so that seems plausible premise 2 says that the human brain is a computer now that might strike some of you as obviously false but you can see the motivation for this statement when you take a look at contemporary cognitive science which has developed since 1950 is under the guiding assumption at the brain is fundamentally an information processing system and that mental functions are implemented in the brain by computational processes of some kind so this premise is plausible in the sense that this theory of mental functioning is plausible to many people working in psychology in cognitive science and in fact something like this is the default view in many areas of cognitive science so the logic looks good and the premises are initially plausible now why isn't this a good argument let's look at the suggestion that was given then maybe this argument is guilty of what's known as the use mention fallacy so what is the use mention fallacy basically a use mention fallacy involves a confusion between a representation and the thing it represents so for example we can talk about my actual son Liam and we can talk about the name we use to refer to him or represent him using the four letter word Liam L I am Liam the boy and Liam the word are two different things one's human being the other is a linguistic object so here's an obvious example of a use mention fallacy I argue as follows premise 1 liam is my son premise 2 liam is made up of four letters conclusion my son is made up of four letters now this is an absurd conclusion so something has obviously gone wrong what's gone wrong is that in the first premise I'm using the word liam to refer to the person in the real world but in the second premise I'm only mentioning the word Liam I'm referring to the word itself not to what the word refers to normally we use quotation marks around a word when we're merely mentioning it to help avoid this confusion in this case it's obviously going on but you can imagine cases where it's less obvious what's going on and your audience might not notice the slippage in meaning in philosophy you can find lots of interesting problems where the slippage is not obvious now with this use mentioned point clarified we can see what's wrong with the argument the word liam isn't being used with the same meaning in both premises for the logic to work right the words have to mean the same thing across the whole argument so when you change the meaning of a key term midway through the argument you break the logic and the conclusion no longer follows so getting back to the question does our original argument all computers are products of intelligent design the brain is computer therefore the brain is a product of intelligent design does this argument commit the use mention fallacy well the answer is no it doesn't we don't have the use mention confusion going on here and I'll explain why in a minute but we do have a related confusion this argument commits what's known as a fallacy of equivocation and the use mention fallacy can be viewed as a type of equivocation fallacy which is a broader category of fallacy so what we mean by equivalent we equivocate when we use the same term and an argument across different premises but we shift the meaning of the term between premises here's a simple example premise 1 a jackass is a male donkey premise 2 my brother Tim is a jackass conclusion my brother Tim is a male donkey this logic works only if the word jackass is used with the same meaning in premise one and premise two but in this case it's clearly not impress 1 the word means male donkey but in premise 2 the word is used to referred to a stupid or idiotic person so we say that this argument equivocates on the meaning of jackass and it's guilty of the fallacy of equivocation now the use mention fallacy is an example of a fallacy of equivocation but it involves a specific type of equivocation namely equivocating between a word itself and what the word refers to now when we go back and look at our argument for the conclusion that the brain is a product of intelligent design we see that it's not guilty of this kind of equivocation it uses the word computer in both premises but neither of these premises is referring to the word computer they're both using it to refer to computers themselves so it's not a use mentioned problem but the argument does equivocate on the meaning of the word computer and this is the source of the problem now exactly well in premise one which says that all computers are products of intelligent design the word computer refers specifically to artificial computers at human beings design and build used in this sense the premise is obviously true actually it's true by definition in premise 2 the brain is a computer the word computer is being used in a much broader sense to refer to any information processing system that performs computations the claim being made is that the brain is a system of this type now this isn't true by definition it's a substantive claim but like I said earlier it's plausible to some people but my point is that this usage of the term computer is much broader than the usage in premise 1 which is talking about the more restricted class of human made computers so there's a slippage and meaning between premise one and premise two and the argument is guilty of equivocating on the meaning of computer now a defender of this argument might want to resist the analysis I just gave and say no she intends to use the same meaning for computer in both premises but this move won't save this argument because if she does use the same meaning for both uses of the term she'll avoid the charge of equivocation but one of the premises will be contentious and the argument will be guilty of begging the question precisely what's at issue now let me explain this for example if she uses the term computer to refer specifically to computers that are products of intelligent design then the first premise is all computers are products of intelligent design and the second premise is when you substitute that meaning of the word computer the human brain is a product of intelligent design but that premise just restates the conclusion it assumes as true precisely what's at issue in the debate now if on the other hand she chooses to use the term computer in the broader sense of an information processing system that performs computations then we can interpret the first premise as saying all information processing systems that perform computations are products of intelligent design and the second premise is the brain is an information processing system that performs computations but now the first premise just begs the question at issue which is whether in fact all systems of this kind are products of intelligent design this argument just assumes to be true precisely what is at issue and so doesn't provide any reasons to accept the conclusion so the upshot of this analysis is this if we allow the slippage and meaning between the two premises then the premises are plausible but the argument is bad because it's guilty of equivocation which breaks the logic on the other hand if we don't equivocate and just use one sense of the term computer consistently through the argument then at least one of the premises simply restates the conclusion and the argument is guilty of a different fallacy the fallacy of begging the question well that about wraps up this episode if you're interested in learning more about fallacies and general principles of logic and argumentation i'd encourage you to check out the video tutorial courses that are available at critical thinking tutorials calm I've got a whole course on fallacies members get access to all the videos plus a set of quiz questions that can help you review and test your understanding of the material if you'd like to support this podcast I would also invite you to leave a rating and a comment on iTunes these really do help to promote the podcast and get it into the hands of more people who might enjoy the next episode we'll return to the series on the elements of critical thinking I'll be going over what sets of skills and knowledge and psychological attitudes are most important for critical thinking so see you then you

Channel: Kevin deLaplante

Views: 40,430

Rating: 4.87251 out of 5

Keywords: critical thinking, fallacy, equivocation, begging the question, use mention fallacy

Id: _ij0xVDEdTQ

Length: 12min 46sec (766 seconds)

Published: Fri Aug 20 2010