We are all Philosophers. How many times have you said, I don't believe that? Or, that's true? But, sometimes we're thrown a stopper, when we consider if something is really reasonable in the broadest and most definite sense, to believe. So, it makes sense that reasonable beliefs are logically justifiable and a reasonable belief fairs much better at being true, than an unreasonable belief.
Since childhood we gather beliefs without checking into their veracity and validity, then there are some we do check. A perfect example would be, the child that goes into the department store at Christmas and sees Santa Claus. He believes he actually is a real person, but after a few questions and years he realizes that there is no Santa. : (
The word Philosophy has its origin in ancient Greece where it literally means "The Love Of Wisdom." You could ask what do Philosophers think about? What kind of Wisdom? What kind of love?
If we search hard enough for good reasons for why we have our beliefs, we bring up many odd questions. Questions of philosophy.