Chapter One, Tutorial Two
Simple Arguments

The following passage provides an "argument", that is, it contains reasoning or evidence for a conclusion.

Sara and Beth are students in Logic 101 and are identical twins. Like many such twins, Sara and Beth share more than just physical traits: they tend to behave in similar ways, share interests down to very specific details, and are emotionally very similar. So, one can conclude with some confidence that Sara will love logic just in case Beth does.

Before moving on, make sure you can identify the conclusion of this argument.

Notice that this argument is not particularly combative.

Interpreting Arguments

We can express our natural language reasoning in many ways. Here's are example from above again:

Sara and Beth are students in Logic 101 and are identical twins. Like many such twins, Sara and Beth share more than just physical traits: they tend to behave in similar ways, share interests down to very specific details, and are emotionally very similar. So, one can conclude with some confidence that Sara will love logic just in case Beth does

Here the premises come first followed by the conclusion. Also, identifying the conclusion is easy: it follows the words "so, one can conclude". Clearly, reasons are given to persuade you: we have an argument. OK...

But other passages expressing arguments will be harder to interpret..

• There may be no indicator words like "so one can conclude" to indicate a conclusion.
• Sometimes premise and conclusion order will be different from the above example.
• At other times, extraneous claims will be made which are not parts of the argument.
• And frequently no argument at all will be made in a passage.

So, we'll need to work on identifying arguments and their structure within a passage. Let's begin with the first of these concerns. Passages that look opinionated might or might not include an argument. We need to think about "distinguishing arguments and non-arguments ".

Distinguishing arguments From Non-Arguments

We need to keep in mind that there are many types of thinking that do not give arguments. So, here are five types of passage that you should be able to disentangle.

• An argument ...gives reasons meant as evidence to support a conclusion, to show it true or likely true.
• An explanation...gives reasons but is meant to show why something is the case...if you notice that the lights go out, and ask why, then I tell you it’s a power failure. I’m not trying to convince you that the lights are out -- you already know that! The explanation gives an account showing how and why the lights happen to be out.
• A conditional statement...if P then Q...as we’ve seen, these statements can be either premises or conclusions but they are not whole arguments. Think about MT or MP. A conditional is a part, but only a part, of arguments of these forms.
• A report...just describes. But a description can sometimes be mistaken as an argument. For example, I may describe all the reasons I love Mexico. This description may be relevant to some conclusion you have in mind (“we should all go to Mexico this spring”?); but if the conclusion is not at least implicitly drawn, the passage is just a report.
• An illustration...gives an example but sometimes in a way that can appear to be an argument. “Philosophers are often picky about language. Thus Halpin doesn't like me to say ‘I know it’ when I should say ‘I think so’.” Here the word “thus” means “so, for example” rather than “so, here’s my reason”.

Moving on...

To begin, read the following passage and click on its conclusion.

(Note that this one sentence passage in the box is made up of several component statements. Each of these is in blue. Click on the one expressing the passage's conclusion.)