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Unit 2 Arguments

Learning outcomes

By the end of this unit you should:

  • be able to recognize and explain a logical argument
  • have practised discriminating arguments from unsupported assertations
  • have critically evaluated a simple argument
Rubik

Text types

Activity 1 Reading

Read the following four short texts and identify which one is an argument. Explain how you decided.

  1. I broke the brand new widescreen monitor in my lab. My supervisor went crazy. He shouted angrily at me. I told him many times it was not my fault, but he continued to blame me. I still think he is wrong.
  2. Create the content in html. Format the styles using css. Control the behaviour of the DOM with JavaScript. Server-side interactions can be controlled using PHP and MySQL.
  3. I was worried that I had a fever, so I took my temperature using a thermometer. The reading on the thermometer showed 36.8 degrees celcius. My average body temperature is around 36.6 decrees celcius. I don't have a fever.
  4. Mathematics is the most important subject taught at schools in Japan.

There are many different types of texts. Texts that move from evidence to claims or premises to conclusions contain arguments. Texts that do not contain arguments include, for example stories (narratives), orders (commands) and descriptions. A particularly important text type is assertions. This is when a claim is made but no evidence is provided. Politicians and sales executives frequently make use of assertions to convince people. Many assertions are false, but some are true.

Activity 2 Listening

Listen to this explanation of how to identify an argument and then the explanation of the four text types in Activity 1.

angry supervisor
thermometer

Identifying arguments

A logical argument comprises evidence and a claim. The premises are the evidence. Then using some reasoning an inference is made to reach a conclusion. To identify whether an argument is present, first identify the conclusion and then find the premises that can be used as evidence. One way to check whether a statement is the conclusion is to place "Therefore" before it and see if it makes sense. Even if the evidence is weak and the conclusion is false, the combination of premises and a conclusion makes an argument.

Activity 3 Thinking

Identify which of the following short texts are arguments. The arguments may or may not be logical.

  1. Bananas are yellow. Strawberries are red. Apples are red or green.
  2. Bananas are fruit. Fruits are sweet. Bananas are sweet.
  3. This activity is too easy for me.
  4. The Earth is similar to Io, the moon of Jupiter. There is life on Earth, so there is also life on Io.
  5. The Earth is similar to a tennis ball. There is life on Earth, so there is also life on a tennis ball.
  6. If you want to decide whether a text is an argument, identity the conclusion. Then see if you can identify the evidence or premises.
  7. Each human has a heart. Professor X is human. Professor X has a heart.
  8. Donald is a duck. The president of the United States is Donald. The president is a duck.
  9. Some Chinese attended class. Aiko attended the class. Therefore, Aiko is Chinese.
  10. Professor X said that here is a rabbit on the moon. You cannot prove that there is not. Therefore, there is a rabbit on the moon.
  11. A man was found in a classroom this morning. His face was cold and blue. He did not need hospital treatment. He just washed the blue ink off his face.
  12. I will definitely get an A in this course.

Activity 4 Listening

Listen to these explanations of the arguments above.

“Logic is the beginning of wisdom, not the end.” – Spock (Leonard Nimoy).

Knowledge and application

Knowledge and application activities are designed to help you activate the key terminology and apply the concepts covered in the course so far. Try to use the terminology and concepts accurately and appropriately.

Activity 5 Audio recording

Submit an audio recording (approximately 60 seconds) via ELMS critically discussing one of the texts in Activity 3. The recording can be in English or Japanese. Your audio file may be uploaded for other students to listen to. Do not state your name or personal information! Speak clearly. Your text is decided by the final digit of your student id number. See the list below.

  • 1: text 1
  • 2: text 2
  • 3: text 3
  • 4: text 4
  • 5: text 5
  • 6: text 6
  • 7: text 7
  • 8: text 8
  • 9: text 9
  • 0: text 10

Activity 6 Writing

Critically evaluate the short passage below. Each sentence is numbered for ease of reference. Identify the conclusion, premises and reasoning. Discuss the truth of the premises, validity of the argument, and the soundness (or cogency?) of the conclusion. If this is a valid argument, name the argument. If this is not a valid argument, state why. Submit your work through ELMS.

Professor X

  1. Professor X is a world famous researcher who drinks a lot of coffee.
  2. Kaoru decided to study in the lab of Professor X.
  3. Kaoru wanted to be a world famous researcher and so started to drink coffee.
  4. Twenty years later, Kaoru became a top researcher.
  5. This proves the positive effect of drinking coffee.
coffee cup

Review

Make sure you can explain the following 9 concepts in simple English:

  • validity, truth, soundness
  • logical indicator, inference bar
  • subject, predicate, end term, middle term

Running count: 22 of 108 logical concepts covered so far.