The Uses of Argument What is an Argument For our purposes an argument is a set of two or more true or false sentences One of which is called the conclusion and the rest of which are called premises How are these sentences related to each other in an argument Premises are given to the purpose of providing reasons or logical support for believing or understanding the conclusion Why are arguments important If every true sentence were obviously true then there would be no need for paying attention to arguments That is not the case however so arguments are a way of having reasonable beliefs about non obvious matters Some questions that arguments are useful in answering are Is A true Why is A true Is A True Attempts to convince someone even yourself that some sentence is true is called a justification We are only concerned with normative justifications Normative Justifications are when you convince someone in a legitimate way in other words convincing someone that a sentence is true because there is good reason to think that it is true and a reasonable person ought to believe it Compare normative justification with justifications by deceit Two Kinds of Normative Justification Impersonal normative justification These justifications ought to convince any reasonable person Example a proof that the Pythagorean theorem is true or the fact that H2O is water since many scientists experiments have supported this hypothesis Personal Normative Justification Justifications that only apply to a certain set of people They take the form of If you believe A then you should also believe B All people in the group have to believe A Example If YOU believe The Hobbit is the greatest movie of all time you can t deny that Peter Jackson has made a great movie This is personal because not everyone believes that The Hobbit was a great movie Why is A true Attempts to account for why something is true are called explanations Already grants that A is true because there is a justification Often we have justified beliefs but they nonetheless puzzle us Example Say you loan a friend some ear buds and when you get them back you notice teeth marks on the cord You don t need to be given an argument to convince you that someone chewed them since your senses give all of the evidence You will want an argument to explain why anyone chewed on the cord since that seems strange General Principles and Explanations Given all our experiences and experiments we are quite confident that some general principles hold in the world such as genetic theory Many explanations especially in science are arguments with those well established general principles and laws as premises along with specific details of the situation that is under investigation Example If you want to know why you have the blood type that you have you can apply the principles of genetics to your parent s blood types Some Claims to Explain From the Textbook on Page 9 4 There are more psychoanalysts in NYC than in any other city or for that matter in most countries in the world You could say that more people cause a higher demand Given the larger populations there are also more people who can have those jobs 5 Average Temperatures tend to be higher closer to the equator You could give an astronomical explanation such as it has more direct sunlight 7 Almost no textbooks are more than 18 inches high You could say that this is not practical and there is a low demand for impractical things therefore almost none are made January 15 2013 Why care about language in this class All arguments are presented in language Of course it is not the case that all things presented in language are arguments Example I promise to pay you 20 next week This is a statement not an argument A feature of language that is particularly relevant to critical thinking is the conventionality of language Language only exists when there are conventions roughly accepted rules for the use of symbols We assume what a word is what other people think it means How do conventions work In the United States we drive on the right side of the road where as in England they drive on the left Do we have the only correct standard NO In the United States chips mean thin crispy snacks where as in England chips mean French fries It allows us to distinguish between things Again do we have the only correct standard NO Can words mean anything then In one sense yes You can imagine a world where everyone uses the word chips in the same way that we do differently than we do or not at all In another sense no Given that we the people in this room all speak American English when talking with each other none of us can legitimately use words while ignoring the conventions for these words What would come of you saying that grass is typically blue to mean that the sky is typically blue It just confuses everyone and your statement doesn t change the fact that the sky is blue and the grass is green since these facts are stated in English The It depends on what you mean defense Occasionally this appraisal will be appropriate For example if someone says it is wise to put your money in a bank whether or not that it is true really does depend on what he or she means by bank since we have multiple conventions for using that word More often this appraisal is inappropriate Why is it inappropriate for someone to say abortion is immoral for me but moral for you since we mean different things by abortion Because abortion means the same thing for both people Linguistic Markers Recall from last time that an argument is a set of two or more true or false sentences but it is not just that Socrates is a man All men are moral Socrates is moral For to be an argument you need to add a argument marker such as therefore to the beginning of the third sentence If you add the therefore it clearly indicates that there is a logical connection between the sentences Socrates is mortal is the conclusion since it follows therefore the rest of the sentences are meant to provide reasons for that conclusion Remember we call the supporting sentences premises Words that clearly indicate that a set of sentences is an argument are called argument markers The ones that explicitly point out conclusions are called conclusion markers The ones that explicitly point out premises are called premise or reason markers Examples of Markers Pages 52 and 53 Not a complete list some of those on the list do not always function as argument markers Example She has been enrolled in FSU