More Related Content
Similar to Deductive-and-Inductive-Argument.. logic (20)
Recently uploaded (13)
Deductive-and-Inductive-Argument.. logic
- 1. Analysis of Statements/ Deductive and Inductive Arguments Mr. Zandro Jade Q. Albo Faculty, School of Arts and Sciences
- 2. You know that all sentences are grammatically classified into five main types. These are: 1. Interrogative sentence - When you ask a question like: What time is it? And alternatively, What is my grade in Philo I? You know that you are using an interrogative sentence. 2. Imperative sentence - when you issue commands like Shut the door! and, Put out the fire! You know you are using an imperative sentence. 3. Exclamatory sentence - when you are surprised and utter What a game! or, when you express pleasure and say This is good! You know you are using an exclamatory sentence. 4. Expletive sentence - But if you are daydreaming and you express a desire or a wish like: I hope my business succeed! or I hope to finish my PhD in philosophy! These are expletive sentences. 5. Declarative Sentence - Later
- 3. Let us quote from Wittgenstein again: But how many kinds of sentences are there? Say assertion, question, and command? --- There are countless kinds: countless different kinds of use of what we call symbols, words, and sentences. And the multiplicity is not something fixed, given once and for all, but new types of language, new language games, as we may say come into existence, and others become obsolete and get forgotten the term language-game is meant to bring into prominence the fact that speaking of language is part of an activity, or a form of life.
- 4. Let us now focus our attention on one very important use of language, namely, using a sentence to assert a knowledge claim. The linguistic bearer of knowledge claims is often called a proposition or a statement in the current linguistic convention. Let us describe this language game. You know that interrogative, imperative, exclamatory and expletive sentences are merely uttered. We do not quarrel about their truth because they have no truth value. When you issue a command Shut the door! the command is neither true nor false; and even if the command is not obeyed, the command is not falsified. Similarly, when you exclaim What a game! you have not said anything true or false because you have not made a knowledge claim. These types of sentences have no truth-values because nothing was asserted and nothing was denied.
- 5. The case is quite different when you use a declarative sentence to assert of deny something in the world that can be either true of false. In this case, you have used a declarative sentence to assert a knowledge claim. And you know that the linguistic bearer of a knowledge claim is either the proposition or statement. This use of a declarative sentence to assert a knowledge claim is very important not only in Logic but in Epistemology as well. declarative sentence - is a statement of something Argument- where not talking about raising your voice and verbal battle with each other. A connected series of statements or reasons intended to establish a position or a conclusion.
- 6. Deductive and Inductive Arguments 1. Question or problem to be resolved 2. Example of possible premises that could be offered Example no.1 Where to go for a dinner? The Shop or School Cafeteria? There are two premises 1. The shop is open until 6 pm these are facts School Cafeteria until 5pm 2. (The cafetria has the best bulalo in the area) opinions What if? it is 5 :15 pm and you are asked Should we eat at shop or school cafeteria? Well, the School cafeteria is closed at 5 pm but the shop is Still open til 6pm If youre correct if the facts are true, then your conclusion has to be true. Your only option is The Shop
- 7. AN ARGUMENT IN WHICH THE CONCLUSION NECESSARILY FOLLOWS THE PREMISES, IF THE PREMISES ARE TRUE, THEN THE CONCLUSION IS ALSO TRUE- THIS IS A DEDUCTIVE ARGUMENT.
- 8. What if the case is this it is only 4 pm Should we eat at the shop or school cafeteria? The shop is slightly ok? But the school cafeteria has the best bulalo food In this case the decision to go to school cafeteria cannot be true, the conclusion does not logically follow from the premises, you simply gave an option
- 9. AN ARGUMENT IN WHICH THE ACCEPTANCE OF THE CONCLUSION DEPENDS ON THE STRENGTH OF THE PREMISES IN WHICH THE PREMISES DO NOT PROVE BUT MERELY SUPPORT THE CONCLUSION IS A INDUCTIVE ARGUMENT
- 10. Example no. 2 How many classes to take? Next semester There are two premises: 1. Twelve units is cost 8,000, fifteen is 8,700 pesos these are facts 2. (Taking more classes every semester will get you done faster) opinions
- 11. WHEN DEALING WITH DEDUCTIVE ARGUMENTS DO NOT START WITH A CONCLUSION You must avoid jumping into conclusion if you are dealing with different propositions. Similarly, when making a deductive argument avoid picking out your conclusion ahead of time and then finding ways to justify it and then you need to start by examining and uncovering the premises then follow where those premises lead what logical conclusion can you from the evidence.
- 12. In evaluating deductive argument: you need to ask two questions 1. Are the premises true - facts that at least can be proven true or false, is the restaurant close or not? You can drive to the restaurant to check it out. 2. Is the form of the argument valid? - An argument is valid if it is not possible for the premise to be true and the conclusion to be false. In our example there are no restaurants to choose from and one of them is closed, the conclusion then is to go to the other open restaurant, if the premises are true then it is not possible for the conclusion to be wrong it must be true as well
- 13. IN DEALING WITH INDUCTIVE ARGUMENT: THE CONCLUSION IS SUPPORTED BUT NOT PROVEN, TO A GREATER OR LESSER DEGREE, BY THE PREMISES. In our example the conclusion goes beyond the premises, the conclusion to go school cafeteria is not logically implied by the statement that it has the best bulalo. Maybe your friend does not have a feeling to eat bulalo then he could offer counter arguments to go to the shop instead. In the case of inductive arguments the evaluation process is different than deductive arguments You cannot necessarily prove or disprove the premises nor you can determine if the premises lead inevitably to the conclusion or not?
- 14. In evaluating inductive arguments you should ask the questions: 1. Are the premises true or at least acceptable?- You may find premises that are not necessarily assessed. Rather than facts you will often have matters of opinion. The assertion that the cafeteria is the best bulalo is a matter of opinion over which people may disagree. In this case consider if the premise is acceptable as reasonable. 2. Are the premises relevant to the issue at hand? Next is you need to decide whether that premise in this case the opinion that the cafeteria has the best bulalo is relevant.Is the premise related to the issue at hand? Here it does seem relevant to consider the reputation of the restaurant in deciding where to eat. However, if some says we should eat to cafeteria because there are chicks, you might question whether that reason is relevant to the issue at hand. 3. Is the premise sufficient to justify the conclusion? Is the opinion that the Cafeteria has the best bulalo really enough to base the decision on? Are there other things you might want to consider, you may ask. How long will it wait for the table? Or how good is the service?
- 15. Evaluation of inductive arguments falls into arrange from weaker to stronger Acceptable, relevant, insufficient ---------------premises -------------acceptable, relevant, sufficient Weaker------------------------------------------------------------------------------------------stronger ARGUMENT