Distinguishing Arguments from Explanations

§2.5

Consider the following passage and the map:

The sun is hot, because it is a ball of gases undergoing nuclear fusion, and nuclear fusion releases a great deal of heat.

The use of the particle “because” may lead us to interpret this as argument, along the lines illustrated in the map. And if we knew Propositions 2 and 3, they would in fact give us a reason to believe Proposition 1. However, it is hard to imagine a situation in which someone would know Propositions 2 and 3 without already knowing Proposition 1, so it is unlikely that anyone would ever make this argument. The more natural way to interpret this passage is as giving us an explanation of Proposition 1.

An argument gives one a reason to believe that its conclusion is true, whereas an explanation cites the causes of a phenomenon. That Map 7 contains an explanation, rather than an argument, is illustrated by the use of a gear shape rather than an ordinary circle.

Often when we’re trying to reach conclusions about things in the future, we use premises that are also causes. For example, we might conclude that it’s about the rain by noticing that there are dark clouds and that such clouds cause rain. But when we’re not reasoning about the future, we usually need to know that a proposition is true, before we try to discover its causes. That’s certainly the case in the passage above. We first know that the sun is hot, and then we try to discover the causes that explain why it is.

You can usually tell from context (and sometimes from the nuances of how inferential particles are used) whether a passage is meant to explain a proposition or to argue for it. If you’re unsure, it can help to ask yourself what question the passage is answering about the relevant proposition. If it’s an argument, it will be answering the question “How do you know it?” (or “What reason do you have for believing it?”). If it is an explanation, it will be answering the question “What caused it?”

It is very easy to confuse an explanation for an argument when what is being explained is a person’s beliefs or actions. It is possible to think of a person’s actions or beliefs as effects and to try to explain them, often by citing biographical facts. Suppose that Charlie spanks his children, and we ask ourselves why he does this. Here are two answers we might come up with:

(i) Charlie spanks his children because he was spanked by his father.

(ii) Charlie spanks his children because he thinks it is the most effective way to discipline them.

Notice that (i) gives us an explanation of Charlie’s behavior, by citing things in Charlie’s past that might cause him to behave as he does, but it doesn’t give us Charlie’s reasons for acting in this way. By contrast, (ii) indicates what Charlie’s reasons might be.

Now consider another example in that concerns a belief rather than an action. Suppose that Dana believes that it is wrong to eat meat, and we ask why she believes this. Here are two answers we might get.

(i) Dana’s parents believed that it is wrong to eat meat.

(ii) Eating meat causes suffering.

We can map these two answers as follows:

Map 13 of (ii):

Notice that (i) explains Dana’s belief by citing a factor in her biography that caused her to come to this belief, but it doesn’t give Dana any reason for believing as she does. It doesn’t help Dana or us to tell whether her belief is true. By contrast, (ii) gives something that might be Dana’s reason for believing as she does. It gives an argument that the belief is true.

Explanations of our actions or beliefs treat these behaviors and beliefs as things that just happen to us. But our beliefs and actions don’t just happen to us. You are responsible for the things you do and for the things you believe. This is why you need to think about the reasons you have for your beliefs and actions, and why you need to think about and evaluate other people’s reasons as well, when judging them. Confusing explanations of beliefs (or behaviors) with arguments for them can obscure these reasons.