Logic and Critical Thinking CCC nd Term 2014

Course Instructor

Office: HSH (Ho Sin Hang) 213

Office Hours Tuesday 4:00-6:00PM & by appointment

My gmail.com

Course Website michaeljohnsonphilosophy.com

Course Meeting Times Wednesday 2:30-4:00PM LKKG05 Friday 5:00-6:30PM LKK205

ASSESSMENT

Reading There is no required reading in this class. There is lots of optional reading on the course website. I may give bonus marks to students who can answer questions in class about the optional reading!

Assessment Attendance: 10%. Four homework assignments, each worth 5% of the grade, for a total of 20%. One in-class midterm in March, worth 30%. One cumulative final exam, worth 40%.

Short Homework Assignments Homework assignments will ask you to apply what we’ve learned in class to your own life and experiences. Example…

Out of Context: 1998-present

Broader Context: 1850-present

HW1 Find an example, from your own life and experiences, where a piece of information was taken out of context in a misleading way.

Student Example Source: Erickson Times

Misleading Graphs Source: Erickson Times

Rubric Describe the information taken out of context: 1 mark Describe the claim the information was used to support, and who was making the claim: 2 marks Describe the broader context and why the information presented was misleading: 2 marks Students’ own experience: 1 mark

Late Assignments I won’t accept late homework. Even 1 minute late is late. Sorry.

Attendance Attendance is required and accounts for 10% of your final grade. You cannot get an ‘A’ in this course if you do not attend classes. Every day you don’t attend, you lose 0.5 marks off your final grade, up to a maximum of 10.

Late to Class You will not be counted as present if you show up after I have called attendance. Please be in class on time.

Final Exam The final exam will happen during the scheduled exam period. Exact time/ date TBA. It will consist of multiple choice and short answer questions. It is worth 40% of the total marks.

Norm-Based Assessment

ACADEMIC INTEGRITY

IMPORTANT NOTE Students shall be aware of the University regulations about dishonest practice in course work and the possible consequences as stipulated in the Regulations Governing University Examinations.

5.2a Collusion A student misrepresents a piece of unauthorised group work as his/her own work.

5.2b Falsification of Data The presentation of data in reports, projects or research papers, which is purported to be based on experimental or research work conducted by the student, has actually been invented by the student, copied or obtained by unfair means.

5.2c Plagiarism The presentation of another person's work without proper acknowledgement of the source, whether protected by copyright or not, as the student's own work.

5.2d Anything Else Dishonest For example, submission of same or substantially same work for two assignments without prior approval.

Policy on Cheating I have zero tolerance for cheating. When in doubt, ask me!

Policy on Talking in Class (When You’re Not Contributing) Zero tolerance.

WHAT IS CRITICAL THINKING?

“Critical thinking is the intellectually disciplined process of actively and skillfully conceptualizing, applying, analyzing, synthesizing, and/or evaluating information gathered from, or generated by, observation, experience, reflection, reasoning, or communication, as a guide to belief and action.” criticalthinking.org

What is Critical Thinking? There are two basic decisions to make in life: 1. Decide what to believe: What do I believe? 2. Decide what to do: What do I do?

Deciding What to Believe The things you believe (or disbelieve) are claims. Examples of claims include: Aliens exist = 4. Pocari Sweat is better than Aquarius. You should kill children for fun.

Claims Claims can be: General or specific Clear or ambiguous True or false Plausible or implausible Reasonable or unreasonable Supported by evidence or not…

Example: Theories Scientific theories are claims that are supported by lots of evidence, that integrate lots of our knowledge, and that explain and predict lots of phenomena.

Example: Guesses Guesses are claims that the guesser only believes might be true, or are probably true.

Example: Lies A lie is a claim that is known to be false and is made to deceive you into believing something false.

Claims There are lots of other types of claims: hypotheses, deductions, considerations… A claim is something that is presented as true.

Critical Thinking Is there any evidence to support the claim? Is the evidence reliable and trustworthy? How reliable is it? Should you accept it? Does the evidence actually support the claim? Is there other evidence you should consider?

Critical Thinking Critical thinking involves asking these questions at the right times, knowing how to answer them, and knowing how to use those answers to accept or reject a claim. This is a skills-oriented class. These are the skills we will learn.

You Already Do It You are already a critical thinker. You use critical thinking skills all the time, even if you don’t know it.

Critical Thinking and Skepticism “Skepticism [critical thinking]… is essentially a form of basic intellectual hygiene, something that everyone is capable of to varying degrees and something that everyone should do.” -- Chris Clarke

Critical Thinking as Mental Hygiene “Skepticism is to the intellect as brushing is to teeth. Sometimes we need expert assistance, but the only way it really does us any long term good is if we engage in the practice of mental hygiene as a habit, preferably after each bout of consuming something that might cause problems down the road, whether it’s a bag of chips or an article in the New York Toast.”

Difference “There is one thing where skepticism differs from toothbrushing. There aren’t legions of non-toothbrushers who pour support and money towards cranks that tell them to keep their mouths dirty.” – vaiyt (Comment #20)

Is there any evidence? Claim: Keeping your devices on poses a danger. But is there any evidence that this is true? Are there studies? What do scientists say?

Is there any evidence? Flu season comes and it’s really bad. You should probably get a flu shot. Or should you go to the traditional Chinese medicine shop? They say their medicine can prevent the flu too.

How reliable is the evidence? Claim: Oh, you have a cold? You should get the doctor to prescribe antibiotics for you. Evidence: I got a cold and after a couple days was feeling really bad. I got some antibiotics and two days later, I felt great!

How reliable is the evidence? But this can’t be true. Colds are caused by viruses, and antibiotics only work on bacteria. The story you heard is a case of regression to the mean. Colds usually take care of themselves in 6 days.

Does the evidence support the claim? Companies often pay celebrities and other public figures to endorse their products. Claim: You should buy/ use this product. Evidence: Celebrity X buys/ uses this product. But is it any reason to buy something that some other person is paid to say they like it?

Taishan Landmark in Guangdong

From SCMP “A group of Hong Kong investors have called for laws to regulate celebrity advertising, claiming to have been misled into pouring money into a Guangdong shopping arcade project… They said they had been attracted to invest in the project because of endorsements by local celebrities, including a food critic and a fung shui master.”

Crop Circles

Crop circles remain one of the mysteries of the ages. What causes them? What do they mean? Are they all part of an elaborate conspiracy and hoax? -- WorldNetDaily

Is there other evidence to consider? Claim: Prayer heals the sick. Evidence: My mother had cancer, but then I prayed for her. Her cancer went into remission. But how many people were prayed for and not cured? How many people were not prayed for, but still had their cancer go into remission? Does prayer work or was this just an accident?

Critical Thinking Becoming a better critical thinker involves exercising these skills, asking these questions and finding out the answers, more often and more effectively and in a wider range of circumstances.

LOGIC

Logic This course is called Logic and Critical Thinking, and we will be learning about logic. Logic is a helpful tool for verifying the quality of arguments.

Philosophical Arguments In ordinary English, an argument is where two or more people have different views, and they heatedly or angrily discuss them. In philosophy, it’s when we present certain claims as evidence for other claims. So critical thinking is about evaluating arguments– are the claims presented as evidence true? Do they support the conclusions?

Validity An important concept in logic is validity, a particularly strong sort of evidential support. An argument is valid = if the claims presented as evidence in the argument (the “premises”) are true, then the claim that evidence supports (the “conclusion”) of the argument must be true (cannot be false).

Formally Valid Arguments Ancient philosophers (both Western and Chinese) discovered that you can tell that some arguments are valid by looking at their form alone.

Example Here’s an example of a valid argument form: Evidence: If A is true, then B is true. Evidence: A is true. Claim: Therefore, B is true. Notice that even if you don’t know what the claims A and B are, you know that if the evidence is true, then the claim is true.

Logic Logic is the study of formal validity. We try to find all the valid logical forms. That way, if we ever find an argument that has one of those forms, we will know for sure that it is valid.

Modern Logic It wasn’t until recently that we (or a German mathematician named Gottlob Frege) found a way to find all the valid logical forms. This is the logic we learn about today.

The Limits of Logic Logic isn’t the entire story. It doesn’t have anything to say about the good arguments that are not formally valid, and it can’t identify bad arguments. There’s also another kind of “goodness” for arguments: a sound argument is valid and its premises are true. But logic alone can’t tell us what’s true.

For Next Class Go to the course website: logic-and-critical-thinking-2014/ logic-and-critical-thinking-2014/ Read the reading for next time.