Humans are belief-motivated beings and you are your beliefs. Animals and plants act, but they simply act without an understanding of the context of their actions or why they are acting. Humans have desires, form intentions, and act on their intentions to fulfill their desires and to do that, they need to form beliefs about the world.
Some people believe that they don’t have beliefs. They don’t believe, they “know,” they say. Well, this is their belief, but it is belied by the facts. Setting aside for a moment the difficulty, if not impossibility, of proving you know something, what is knowledge?
What we call “knowledge” is just a type of belief, a belief that we believe we have a high level of evidence that justifies our belief in the belief. And yes, there are a lot of beliefs there. Such is life.
For centuries, philosophers believed that knowledge was “justified true belief.” They never denied that knowledge was belief (only a fool would believe otherwise), but philosophers wanted to say that we could consider some beliefs to be superior to others, i.e. – beliefs we know to be true. Edmund Gettier demolished this belief when in 1963 he published a brilliant short paper entitled, “Is Justified True Belief Knowledge?” Go ahead and click the link, it will take you less than 15 minutes to read the paper.
No paper in the history of philosophy has caused more discussion and uproar than Gettier’s simple little paper. It has spawned a cottage industry in creating examples that prove Gettier’s point. They have come to be known as “Gettier Problems.” Here is one of the better-known ones:
Suppose there is a county in the Midwest with the following peculiar feature. The landscape next to the road leading through that county is peppered with barn-facades: structures that from the road look exactly like barns. Observation from any other viewpoint would immediately reveal these structures to be fakes: devices erected for the purpose of fooling unsuspecting motorists into believing in the presence of barns. Suppose Henry is driving along the road that leads through Barn County. Naturally, he will on numerous occasions form a false belief in the presence of a barn. Since Henry has no reason to suspect that he is the victim of organized deception, these beliefs are justified. Now suppose further that, on one of those occasions when he believes there is a barn over there, he happens to be looking at the one and only real barn in the county. This time, his belief is justified and true. But its truth is the result of luck, and thus his belief is not an instance of knowledge. – Goldman, Alvin. 1976. “Discrimination and Perceptual Knowledge.” The Journal of Philosophy 73, pp. 771-791.
Some who cling to the belief that they have knowledge not beliefs vent their spleens at the Gettier Problems. A weak comeback to the fake-barns problem is that there is a second level of verification that we can get off the road and look from the side and then we “know” whether it is a real barn or a fake barn. But that just moves the issue to a different data point. You now claim that this new belief you have is justified just like you claimed your earlier belief was justified. How do you verify that this new visual sighting is not fake? But this all misses the point of the Gettier Problem. What you call knowledge is just what you believe you are justified in believing. Certainly, some justifications are better than others, but you can never get past the reality that there are beliefs and that there are beliefs all the way down.
The debate rages on with one belief fighting with the other belief. Such is life. But then, you are your beliefs.