Logic in writing• Writing has different purposes.
• To tell a story; to describe something; to entertain• The purpose of much academic (school) orprofessional (job) writing is to explain an idea,
or to persuade someone to believe something.
• Logic can help a writer explain or persuade.

Review: Types of sentences


Questions ask for information.


Greetings mark a relationship between people.


What is the capital of Guatemala?
Good afternoon.

Exclamations or emotional expressions tell how awriter/speaker feels.
Oh my God! That's great!

Types of sentencesStatements give information. Some statements
are good support for writing.
Statements of fact are the best support.
Facts can explain the things you know (explanatorywriting).
Facts can convince people of your arguments(persuasive writing).

Facts versus opinions


Facts are objective statements of truth. They
are outside the individual, and remain true nomatter who says them.
Water boils at 100℃.

Approximately 127,450,000 people live in Japan.

Opinions are subjective statements. They arebased on one person's beliefs or feelings.
Maccha ice cream is delicious.
Students should not be required to take English
classes.

Facts versus opinions

It is sometimes OK to express opinions inacademic papers.
But, topics need to be supported mostly withfacts.
Supporting facts should be as specific aspossible.

What do we do with these facts?
Support your topic sentencewith facts and logical arguments.

Logical argument• Implication: Sometimes one idea implies thetruth of another idea.
• If the river is narrow, we can cross easily.

• In that case, showing the first idea is true will
suggest that the second idea must be true.
• The small river near my house is only two meters
wide. Therefore, we can cross it easily.

Logical argument• Two ideas can be added together to support a
conclusion.
1. Professor Nilep is a Mei-Dai professor.
2. All Mei-Dai professors attended graduateschool.
3. Therefore, Professor Nilep must have attended
graduate school.

Logical argument• Two ideas can be added together to support aconclusion.
1. Organic food does not use pesticides(農薬).
2. Using pesticides can damage the environment.

3. Therefore, organic food is less likely to damage
the environment.

Facts and logic• If the evidence is true and the logic is good,then we can believe the conclusion.
• Therefore, true statements (facts) plus a valid(logical) argument will support your point.

Logic in writing• Develop a logical argument to support yourmain idea.
• What facts do you know?
• What logical ideas connect those facts to your mainidea (e.g. your topic sentence)?

• Write a paragraph that tells the facts and isorganized to show the logical argument.

Logic in writing: Example• MY IDEA: Companies should make sure their
I read this in theworkers take vacation time every year.
New York Times.
• Workers who are relaxed are more productive.
I learned this ineconomics class.

• Companies that are more productive makemore money from the same investment.
I think this is true. I
relax on vacation.

• People who take vacations are more relaxed.

Logic in writing: Example• Logical argument 1:
1. People who take vacations are more relaxed.
2. People who are more relaxed are more productive.
3. Therefore, people who take vacations are moreproductive.

Logic in writing: Example• Logical argument 2:
1. People who take vacations are more productive.
2. More productive workers make the company
more money.

3. Therefore, people who take vacations make thecompany more money.

Logic in writing: Example
Companies should make sure their workers take avacation every year. Time away from work can help
people relax. According to the New York Times,workers are more productive and make fewermistakes when they are relaxed. Employees who aremore relaxed and therefore more productive can help
the company earn more profit from less investment,and vacations can help with this. So if companies want
to be successful, they should encourage their workers
to take time away from work every year to relax andenjoy a vacation.

Logic in writing• Facts and logic can help readers understand anidea that you want to explain.
• Using factual support and logical argument, youcan persuade readers that your idea is correct.
• Explaining and persuading are common goalsof both academic and professional writing.
• Support your topic with facts.
• Organize your writing and explain the logic in a waythat your readers can understand.