Section 2: Advice for Logical Reasoners

All of us use these principles every day, so this discussion is just a reminder of what you already know. One principle is to ask for reasons before accepting a claim or conclusion, unless you already have good enough reasons. You applied this principle when you asked Juanita why she thought it best to leave. Similarly, if you expect people to accept your own claim, then it's your responsibility to give them reasons they can appreciate.

If you expect people to accept your own conclusion, then it's your responsibility to give them reasons they can appreciate.

────CONCEPT CHECK────

Which of the following passages contain an argument in our technical sense of that word?

a. I hate you. Get out of here!

b. I'm sure Martin Luther King Jr. didn't die during the 1960s, because it says right here in the encyclopedia that he was assassinated in Memphis in 1998.

c. The Republican Party began back in the 1850s as a U.S. political party. Abraham Lincoln was their first candidate to win the presidency.

d. I don’t believe you when you say Martin Luther King Jr. could have been elected president if he hadn’t been assassinated.

Try to discipline yourself to read and answer these sample exercises before looking up the correct answer in the footnote below, and before reading on. You do not need to write out the answer. The exercises are designed to test your understanding of concepts in the material you have just read. If you can answer the Concept Checks, then you will be ready to tackle the more difficult exercises at the end of each chapter.

────[1]

Let's continue with our introduction to the principles of logical reasoning. (There are quite a few more principles to be uncovered.) For example, in the camping-trip story, you paid attention both to what Juanita said and to what Emilio said, and you wished there was a park ranger nearby to ask about Giardia. The underlying principle you applied is to recognize the value of having more relevant information. In the camping situation, it would not have been irrational to choose to pack up and go home, but it probably wouldn’t have been the best decision. The point is to make your decision on the basis of a serious attempt to assess the relevant evidence. You did this when you paid attention to probabilities and consequences—you weighed the pros and cons—of going or staying. That is, you weighed the benefits and drawbacks.

[1] The answer to the present Concept Check is (b), even though there is an error in the encyclopedia because King was really assassinated in 1968. Choice (a) is not the correct answer because, although it does show two people having a dis­agreement, neither one is arguing in our technical sense of “argument,” because neither is giving reasons for what is said. Choice (c), on the other hand, merely describes the Republican Party. One moral to draw from this Concept Check is that an argument based on incorrect information is still an argument; a bad argument is still an argument. A second moral is that an argument can have just one reason, although most arguments use more than one.