Perception is the automatic integration of sensory stimulus.
It is not a form of thinking, in that one's ideas do not affect the process.
Perception is automatic and independent of volition.
Perception is an integration of stimulus.
It combines different sensory effects over time into a single unified whole.
The result is the awareness of entities.
We don't see a mass of different colors and brightness.
Instead we see a computer monitor,
a book, or a cup of grape kool-aid.
We see things.
This is different then knowing what we see, though.
That knowledge is not automatic.
An example is a scientist's laboratory.
If you walked in, you would see objects of different sizes, shapes, colors, etc.
You may have no knowledge about what they are, or what they are used for, but you would
perceive them as objects --
as integrated wholes.
Perception is the base of all knowledge.
We acquire raw information about the world around us through perception.
We can then take that information and integrate and try to understand it.
All knowledge, though, is derived from this common root.
What we perceive.
It is our link to the outside world.
There is never a question that what we perceive is accurate.
The only question is whether we accurately interpret what we perceive.
The way to do this is through reason.
(This page mirrored from Importance of Philosophy.com)