2.3: Identifying Arguments in their Natural Habitat

The first step in deciding whether something that you read or hear is an argument is to determine whether it has a conclusion and (if so) what that conclusion is. Once you identify the conclusion, you can usually figure out the premises. So, you should always begin by looking for the conclusion.

Indicator Words

Some words are good indicators of a conclusion; the typical job of these words is to say, ‘here comes the conclusion’. To discover what these words are, consider a very simple argument:

Premise 1: All humans are mortal.

Premise 2: Socrates is a human.

Conclusion: __________, Socrates is mortal.

The last sentence of this argument is its conclusion. To discover some conclusion indicators, just ask yourself what words could sensibly be placed in the blank before the last sentence (think about this and write down several before proceeding). Some natural words and phrases to put in the blank are: ‘therefore’, ‘hence’, ‘and so’, ‘thus’, ‘consequently’, and ‘it follows that’. Sometimes the conclusion of an argument comes at the beginning, rather than at the end. In this case, any indicator words will come after the conclusion. To see how this works, we’ll just rearrange our argument a bit.

Conclusion: Socrates is mortal.

Premise 1: __________ all humans are mortal [and]

Premise 2: Socrates is human.

What words can sensibly go in this blank (write some down before proceeding)?

Some natural choices are ‘because’, ‘for’, and ‘since’. These words usually say, ‘here comes a premise’.

Conclusion Indicators: ‘therefore’, ‘thus’, ‘so’, ‘hence’, ‘consequently’, ‘accordingly’, ‘entails that’, ‘implies that’, ‘we may conclude that’, ‘this establishes that’, ‘this gives us reason to suppose that’, ‘in short’...

Premise Indicators: ‘because’, ‘for’, ‘since’, ‘after all’, ‘inasmuch as’, ‘in view of the fact that’, ‘in virtue of’, ‘here are the reasons’...

These lists are not exhaustive, but they include the key indicators. In most cases, our rules of thumb for identifying premises and conclusions, based on the occurrence of these indicator words, work well. But there are exceptions, so our guidelines are never a substitute for thinking about the example yourself.

If arguments came neatly packaged and labeled like the two we’ve just seen, things would be easy. But in real life, arguments often do not contain any indicator words at all. When this happens ask yourself: what is the other person trying to get me to believe? Once you figure this out, you’ll have the conclusion, and then it should be relatively easy to locate the premises. Sometimes in real life, things are even more unclear.

Sometimes a premise of an argument isn’t explicitly stated; other times the conclusion is missing. There are often good reasons why parts of the argument aren’t stated. Sometimes they are obvious enough in the context that they “go without saying.”

One or more unstated premises are common when the premises include information that is widely known, obvious, or easily figured out in the context. And an unstated conclusion often occurs when the conclusion is thought to follow so obviously from the premises that it would be insulting to your intelligence to spell it out for you.