Epistemology is the part of Philosophy that studies the nature of Knowledge.
(Greek Epistēmē = Knowledge)
Sensing is our primary tools to gain knowledge.
Can we also use Intelligent Reason? Can we use Belief?
We can See the colors of nature, we can Hear the birds, we can Smell the flowers, we can Taste the fruit, we can Feel the heat of the sun.
Man can also understand abstract knowledge:
How do we gain abstract knowledge?
Most people believe that a God exists, even if it cannot be proven by reason.
Some believe that every man is created by God. Some believe there are Angels.
Some people will need no justification. Faith is enough.
Some people will justfy their Faith by referring to episodes where God has spoken directly to living persons.
The theory that it is possible to understand reality without intelligent reason is called mysticism.
Is there an other reality in addition to the one that we can see and sense?
Is it possible to gain knowledge about this other reality by using other forms of cognition than senses and intelligent reason?