We will distinguish between two types of arguments—inductive and deductive—to help us analyze arguments effectively. All arguments are either deductive or inductive. In this section I will cover what induction is and how to spot an inductive argument.

Definition of an inductive arguments: An argument where the premises are intended to give uncertain reason to believe the conclusion. Simplified: an inductive argument makes the conclusion probable, but not certain.

Step 1: Identifying an inductive argument

To recognize an inductive argument, ask yourself if there is any possible situation where the premises are true, but the conclusion is false. If such a situation exists, then the argument is inductive.

Examples of inductive arguments:

1) Most birds can fly,

2) Penguins are birds,

3) Thus, penguins can probably fly

1) The majority of ravens are pink,

2) Thus, the next raven born will probably be pink

If you identify that an argument is inductive, move on to step 2. If an argument is non-inductive, do not move on to step 2 (since an argument cannot be strong if it is not inductive).

Step 2: Determine if the argument is strong:

Definition of strength: An inductive argument is strong if the presumed truth of the premises makes it likely that the conclusion is true.

To determine if an inductive argument is strong, imagine that the premises are true and you have no other information. In this situation, is the conclusion likely? If so, then the argument is strong.

Examples of strong arguments:

1) My grandma has always given me $10 on my birthdays,

2) Tomorrow is my birthday,

3) Thus, my grandma will probably give me $10 tomorrow

1) Most moons are made of cheese,

2) Thus, our moon is probably made of cheese

If you identify that an argument is inductive and strong, move on to step 3. If an argument is not both inductive and strong, do not move on to step 3. An argument cannot be cogent if it is not both inductive and strong.

Step 3: Determine if the argument is cogent

Definition of cogency: An inductive argument is cogent if it is strong, and it has true premises.

To determine if a strong inductive argument is cogent, go through each premise, ask yourself, are these premises true in the real world? If every premise is true, then the argument is cogent.

Examples of cogent arguments:

1) The majority of cats I’ve met meow,

2) Thus, the next cat I meet will probably meow

1) The majority of planets in our solar system have multiple moons,

2) The Earth is a planet in our solar system,

3) Thus, the Earth probably has multiple moons

Comprehension Questions