Premises and Conclusions

1. Review of Arguments

watch

Check out this video to review the components 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.

When we analyze an argument philosophically, we call the various “parts” of the argument propositions. (These “parts” are not necessarily sentences because a sentence might include multiple claims in an argument.) Some of these propositions are intended to give evidence for the proposition that is being argued for. The propositions that do 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 you need to support for it to be accepted as true. You thus need some premises to support.

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., by 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 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.

terms to know

Proposition

A claim made as part of an argument.

Premise

A proposition that is intended to provide evidence or support for other parts of an argument.

Conclusion

A proposition that states what the argument is intended to prove.

2. Identifying Premises and Conclusions

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 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. Here 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 earlier. Let’s go through them to see which indicators were used. Click each one to see more.

Argument 1: Since the policy has failed to deliver on its promise, new directions need to be considered.

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.”

Argument 2: There is no milk left, so I can’t bring you any.

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.”

Argument 3: I won’t be able to make it on Sunday because the buses aren’t running that day.

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.”

Argument 4: There are fewer homes than are needed; thus, there should be greater investment.

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.