How Arguments Can Go Wrong

What are the parts of an argument?

Arguments are built out of premises and conclusions. For example, here is a simple argument:

All cats are mammals.
All mammals feed their babies milk.
Therefore, cats feed their babies milk.

The first two sentences are the premises. The last sentence is the conclusion. Premises are statements that support the conclusion.

If the premises are true and the logical structure is valid, the conclusion is also true.

How Arguments Can Go Wrong

There are two main ways arguments can go wrong.

1. One or more premises are incorrect.

For example:
All fruits are purple.
Bananas are fruits.
Therefore, bananas are purple.

The logic in this argument is valid, but the first premise is false.

2. The logic is flawed.

For example:
Horses are mammals.
Cats are mammals.
Therefore, horses are cats.

In this argument, the premises are correct, but the logic is flawed. Arguments with flawed logic are called invalid arguments.

Important Note

An argument can have false premises and/or flawed logic and yet still have a true conclusion. For more on this, read How Flawed Arguments Can Go Right.

The ways an argument can go wrong are covered in Critikid's course Logic for Teens.