Question

When two ideas are used to prove each other, we call this ________ reasoning?

Answer 1

Circular.

Explanation:

The term is somewhat self-explanatory-- circular reasoning goes in circles. Essentially, by circular reasoning, A is true because B is true, and B is true because A is true.

(Simplistic) Example:

Jake is awesome.
"How do you know that?"
I know that because he's cool.
"How do you know he's cool?"
I know he's cool because he's awesome.