Premises and Conclusions

1. Review of Arguments

To begin with, recall the nature of an argument. If you want to make an argument, then you want someone to agree with something. To do that, you must give them a reason to agree with you. In other words, you must give some support for whatever it is that you want someone to accept. What does the supporting are called the premises, and what is supported by the premises is called the conclusion.

The premises are statements that claim to say something true of the world. This is called a factual claim. The way you get from the factual claim to the conclusion is by saying that the conclusion follows from the supposed facts you provide.

IN CONTEXT

Imagine you want to convince your teacher you didn’t skip school. The statement “I didn’t skip school” is the conclusion that you need to support in order for it to be accepted as true. You thus need some premises to do the supporting.

For instance, you might make the factual claim: “I was at the doctor’s.” Assuming that the truth of this premise can be established (e.g. a doctor’s note), then the conclusion, “I didn’t skip school,” is supported by the premise, “I was at the doctor’s.”

In this context, the claim that the premises do support the conclusion is called the inferential claim.

big idea

Arguments are a group of statements containing both a factual claim or claims and an inferential claim or claims.

2. Identifying Premises and Conclusions

In order to see if an argument works or not, you need to be able to distinguish the premises from the conclusion—that is, you need to separate out which part of the argument is intended to do the supporting, and which part is intended to be supported.

Often you can do this by looking out for certain words that indicate whether someone is offering a premise or a conclusion. Below are a few examples.

try it

Consider these four arguments and see if you can identify the premises and conclusions with the aid of the indicators listed above.

Let’s go through them to see which indicators were used.

1. We know that the statement “the policy has failed to deliver” is the premise because the word “since” is used. This premise is supposed to support the conclusion that “new directions need to be considered.”
2. The conclusion “I can’t bring you any” was indicated by the word “so.” The conclusion is supported by the factual claim that “there is no milk left.”
3. Here the fact that “the buses aren’t running” on Sunday is offered as a reason or support for the conclusion that “I won’t be able to make it.” This is indicated by the word “because.”
4. We can see that the conclusion is “there should be greater investment” because of the word “thus” directly before it. The statement “there are fewer homes than needed” is the premise offered in support of that conclusion.