So our beliefs are contrasted with one another and compare the beliefs of this increase or decrease its credibility. If a belief is inconsistent with the rest of our beliefs, you probably dismissed it as a valid belief. A good example of this mechanism are the dreams. Dreams are dreams and realities considered because they are inconsistent with the rest of our beliefs. Similarly an optical illusion (an illusion in road appears to be a pool) is considered illusion, not reality, because it contradicts most of our beliefs (the pools of water do not go away quickly when we approached them.) Making decisions based on our beliefs: Human beings are trying to increase pleasurable sensations and feelings and to reduce the unpleasant sensations and feelings.
For that we make decisions based on our beliefs imagining the possible consequences of our actions. In short, human beings feel, simple assumptions we make based on what we feel making such assumptions in beliefs, we try to make our assumptions are consistent, so we scrapped the assumptions more inconsistent with our beliefs, and perform actions based on these beliefs, trying to maximize our happiness. The actions are likely to produce new insights that will make us to expand or modify our prior belief system. Scientific laws are established and modified using the same mechanism of assumptions and beliefs contrast. After many experiments, the scientists established that two planets are attracted with a force proportional to the product of their masses and inversely proportional to the square of the distance that separates them.