Logical thinking 2 True in part, true for the whole

Generalizing about groups or properties can be problematic

Using sound logic is vital for advanced communication, it will also help you answer questions clearly in meetings, presentations and conversation. It will also help you get better scores on logical aspects of English speaking tests.

Introduction

We'll look at how people can confuse specific information with general information, and we will discuss ways to accurately attribute information.

Warm Up

A man reasoned that since we can't see atoms, and you are made of atoms, you must be invisible.

We can agree that he is incorrect, but why is he incorrect?

Language

Let's talk about generalizing. When something is true for the whole, it may or may not be true for one part, and vice versa. For example:

Japanese people eat rice, and Junko is Japanese, so Junko definitely eats rice.

Do you think this is fair?

To point out a fallacy, You can start with these kind of phrases:

  • I don't think it's safe to say...
  • Actually I don't think...
  • I'm not sure I agree that...

We can, however, draw tentative conclusions. Imagine Junko is coming to your house for dinner, and you are thinking about making a rice dish. Would you ask Junko if she eats rice, or would you assume that she does? To discuss generalizations, we can use these phrases:

  • In general...
  • From my understanding/ experience...
  • As far as I know...
  • I think we can agree that...
  • ...most...
  • ...nearly all...

Discuss properties of groups in general with your instructor. What can you say about people who live in your area?

Practice

Try to refute and clarify these arguments. Is it true in part, completely true, or completely false?

  1. Cows are black and white. My cup is black and white. Therefore, my cup is a cow.
  2. Fuel costs have been decreasing, so it's safe to say that the price of airplane tickets will decrease in the foreseeable future.
  3. Marc Jacobs clothing is expensive, and that person's shirt says "Marc by Marc Jacobs" so the person must have paid a lot for their shirt.