Structure of an Argument
You are probably already familiar with the word “argument” as its used quite often in casual conversation. In everyday parlance, argument means a spat or disagreement between two or more individuals over a particular topic. However, in the lingua franca of logic, the definition of an argument is further expanded to incorporate “a statement, reason, or fact for or against a point.” In other words, an argument is the reasoning constructed to support a position on x, y or z.
Structure
Now that we have properly defined an argument, let's move on to its structure within logic. An argument is composed of the following:
Premise
Turnstile
Conclusion
That's it; just three parts compose the reasoning for every human's world view who has ever existed or will ever exist. Anything that falls outside of this particular structure is not considered to be an argument. It could be advice, a belief, an explanation, presenting a fact, or other types of non-arguments.
The premise is a proposition which give reasons, grounds, or evidence for accepting the conclusion. The turnstile is a word or phrase such as thus, therefore, etc. that immediately precedes the conclusion. Last, the conclusion, is the proposition which is inferred from the premises. Note, some sources do not consider the turnstile to be a part of an argument and will just refer to the premise(s) and conclusion as the components of an argument.
Examples
Let's examine the following argument:
Only mammals have hair.
Dogs have hair.
Therefore, dogs are mammals.
Here, the premises are the propositions “only mammals have hair” and “dogs have hair.” The turnstile is the word “therefore,” which is immediately followed by the conclusion “dogs are mammals.” That's it; a simple, instructive example of an argument, which happens to have a true conclusion. Let's try another:
It generally rains on Wednesdays in April.
It's April and tomorrow is Wednesday.
Therefore, it will rain.
In this example, the premises are “it generally rains on Wednesdays in April” and “it's April and tomorrow is Wednesday.” Following the turnstile “therefore,” the conclusion is “it will rain.” However, unlike our example before, the conclusion of this argument isn't necessarily true (i.e., there's a possibility it could be wrong).
Let's try another argument that's more germane to pseudo-scientific arguments that are often encountered online:
My neighbor's child started to show signs of autism after having multiple vaccines around the age of one.
Thus, vaccines cause autism.
There is only one premise here which is the proposition “My neighbor's......age of one” and the conclusion is “vaccines cause autism.” Now, as we know due to the preponderance of scientific evidence [1] showing no link between vaccines and autism, the conclusion is false. The error in this argument occurs in the premise. Specifically, a false cause logical fallacy (i.e., correlation doesn't mean causation) was committed, which renders the entire argument bad.
Hence, the owner of the argument should replace it with a new argument; hopefully, one that doesn't contain a logical fallacy. If the new argument again contained a logical fallacy, it would have to be rejected once more. More on the formal definition of a logical fallacy, the various types, and when it’s appropriate to reject an argument later.
Last, consider the following:
There is an abundance of false information on the internet these days. Everywhere I look, there’s some influencer spreading health disinformation or a friend sharing global warming misinformation on social media.
Critical thinking is a great way to protect yourself from false information.
Are you slightly confused here as to what you should label as the premise(s) and the conclusion? In general, the conclusion is the last proposition, while the propositions that precede it are considered the premises, but that doesn’t quite work here. The reason this doesn’t work as this isn’t actually an argument; it’s advice. I’m not arguing that you should learn critical thinking, but simply advising that critical thinking protects from false information. However, this advice could be used as part of an argument. Consider the following adjustment:
There is an abundance of false information on the internet, particularly social media, these days. Everywhere I look, there’s some influencer spreading health disinformation or a friend sharing global warming misinformation on social media.
Critical thinking is a great way to protect yourself from false information.
Thus, you should learn critical thinking.
With the addition of the last line, I am now taking what was originally advice and using it to argue in favor of you learning critical thinking (i.e., the conclusion of the argument). Again, advice on its own is not an argument.
Conclusion
At this point, you should be quite comfortable with the definition of an argument on your quest for critical thinking mastery. The premise, turnstile and the conclusion are the pieces that compose every argument that has ever been made or will ever be made. While the words that compose each piece may be different, the structure is always the same. Keep in mind that these arguments we tell ourselves and those around us are what we use to shape our worldview. Therefore, it is paramount that these worldviews are built from a solid foundation of good arguments.
References
[1] CDC. Vaccines Do Not Cause Autism.