One of the biggest problems I find in philosophy is that far too many philosophers misunderstand knowledge. They often fall into the trap of thinking that there are only two types of knowledge: a priori knowledge and a posteriori knowledge.
A priori knowledge is knowledge that is gained by faith alone.
A posteriori knowledge is knowledge that is based off of experience.
This distinction seems to leave out the most important type of knowledge: faith knowledge.
Most people find my beliefs that the earth orbits the sun or that there is mostly empty space in desks, or that there is a war going on in Iraq to be reasonable ones. Now I really have no knowledge that the sun orbits the earth, there are atoms in desks, or there is a war going on by reason alone. I also have no real reason to believe from experience that what makes up desks is mostly empty space with atoms, or that the earth orbits the sun, or that there is a war going on. There could certainly be other plausible explanation for what I experience, namely that the sun orbits the earth, or that desks are tightly filled with atoms with little or no empty space, or that the war in Iraq really is really just being made up. The problem is too many philosophers forget that most of what we know we accept from RELIABLE sources. Because they don’t understand this they often reduce themselves to skepticism when they cannot find a priori or a posteriori knowledge. Even philosophers who aren’t skeptics often find ways to damage their philosophies by baseing them around a priori and a posteriori knowledge.