I watched a movie called “inception” few days ago. The basic content of the movie “Inception” is that a group of people tries to plant a belief in the subconscious mind of a targeted person.

The main character of the “inception” called Cobb had said that “it is possible to lose your grasp on what is real and what isn’t real.” Then, to differentiate the dream from the reality, what the characters need are the totems. The totem is an object that allows the character to examine the real world logically. This also means that only with the sense perceptions, the characters would easily confuse the dream and the reality. Then a knowledge question came across my mind: To what extent are our senses reliable?

Everyday we use different ways of knowing to apprehend the world, but most of people agree that the perception is a vital source of knowledge. Sense perception is based on the usage of five senses–the five senses having the ability to see, hear, touch, taste and feel. Without them, humans would be unaware of many things in the world. In other words, losing one senses means losing a capability to perceive certain things. Since we rely on sense perception in most time, sense perception seems like a good, logical way to determine whether we are in a dream because the senses are only triggered by real objects. For example, scientific methods use sense perception to prove or disprove a certain theory. When the scientists are doing the experiments, they make the observation about the products.

On the other hand, some people argue that we should not rely completely on the senses to justify what is true. When we are collecting the information and gaining the knowledge, we use the brain. The senses input the information and the brain analyze and interpret the information. The senses are controlled by the brain, so even if we are not feeling something physically, our mind can make us believe we are.

In addition, the brain is not the only factor that obstructs us to justify what is true. Our senses can sometimes be altered by environmental, emotional or physical factors, such as stress and extreme temperature. For instance, some people in the desert claim that they had seen an oasis in the middle of the desert. However, what most of these people experience is the hallucination, which is defined as a perception in the absence of external stimulus that has qualities of real perception. In the desert’s case, the cause of the hallucination is the extreme heat. This extreme heat affects the people’s ability to perceive the real situation.

There is another alternative explanation that why sense perception can’t be the only one way of knowing to understand the world. That’s in order to the limitations of human sense perception. Every sense has the limitation. For example, there is the hearing range for the human. Human only can hear about 20 to 20000 Hertz sound, and this tends to decrease with age. For another example, dogs have a very well-developed sense of smell, whereas human don’t have. Due to the different sense organs, each has different perception of the world. Therefore, to fully perceive the world, other ways of knowing, such as language–to share the knowledge–, are needed.

In conclusion, although the human sense perception has some limitation, it is reliable. However, it would become unreliable because other complex factors, such as the mind, affect the justification of truth. In other words, the sense becoming unreliable isn’t due to sense perception itself, but other things. For instance, even though the sense perceptions provide the correct information, if our mind analyzes the information in improper way, we would incorrectly perceive the world.