Theory of Knowledge: Skepticism

Theories of knowledge aim to improve people’s understanding of how knowledge is formed and how truth can be distinguished from false information. Hence, various theories of knowledge also deal with the reliability of the information. Skepticism is a philosophical notion that “there are grounds for doubting claims that we typically take for granted” (Fieser, 2019, para. 5). The present paper will seek to describe the key premises of skepticism and explore the reliability of knowledge from the viewpoint of this theory.

As with most other theories, there are various types of skepticism. As explained by Fieser (2019), scholars distinguish between them based on the extent of doubt expressed by the skeptic, and the core notions are radical skepticism and limited skepticism. In limited skepticism, the focus is on the particular claim, which can be doubted due to the poor reliability of information supporting it (Fieser, 2019). Radical skepticism, in turn, maintains that all knowledge can be questioned (Fieser, 2019).

The latter form of skepticism is somewhat more interesting since it doubts all knowledge, regardless of its origin. This position affects not only the reliability of the information itself but the entire process of creating and interpreting data. On the one hand, it appears counterproductive to think that all knowledge is unreliable because it negates the efforts of scientists and scholars to form new knowledge and test existing information. On the other hand, there are some grounds for the beliefs of radical skeptics, which should be considered while evaluating this theory.

There are four primary sources of knowledge for people: perceptions, memory, introspection, and reasoning. In line with the tenets of radical skepticism, each of these sources of knowledge can be unreliable. Firstly, sensory perception is a significant source of knowledge that is tied to the ability of beings to see, hear, sense touch, taste, and smell (Fieser, 2019). However, sensory perception depends on the interpretation of stimuli by the brain, and it may be prone to errors (Bruno & Rutherford, 2017). For example, people with complete color blindness, known as monochromacy, perceive the world as black and white. While their perceptions may be accurate to them, they are hardly the source of truthful knowledge.

Secondly, memory is considered to be among the sources of knowledge. There are different types of memory, all of which ultimately rely on how our brain processes information (Fieser, 2019). It is common for people to get their memories mixed up or interpreted in the wrong way. Memories can miss important details or distort information in a way that changes its meaning entirely. For instance, people can easily forget the time of their doctor’s appointment or the items on their shopping list.

Introspection and reasoning are the final two sources of knowledge, and both have their weaknesses. Introspection involves people’s experiences of certain mental states (Fieser, 2019). Introspection is often subject to bias because people may fail to distinguish between their feelings or attribute their feeling to an appropriate cause. For example, a person might think that they are nervous because they forgot something while they are experiencing anxiety due to an upcoming deadline. Reasoning, although considered by many as the most reliable source of knowledge, is still subject to bias (Bruno & Rutherford, 2017). For instance, confirmation bias can cause a researcher to believe that one variable impacts the other, even if other factors could have impacted the dependent variable.

Overall, it is true that sources of knowledge are subject to doubt. However, admitting the fact that some knowledge is unreliable does not mean that all information is inaccurate because there are ways of improving the reliability of knowledge. In responding to a skeptic, I would argue that the reliability of information may be increased when the same piece of information can be derived from all four sources of knowledge, or when many people agree on their experiential knowledge.


Bruno, G. A., & Rutherford, A. C. (Eds.). (2017). Skepticism: Historical and contemporary inquiries. New York, NY: Routledge.

Fieser, J. (2019). Chapter 6: Knowledge. Web.

Removal Request
This essay on Theory of Knowledge: Skepticism was written by a student just like you. You can use it for research or as a reference for your own work. Keep in mind, though, that a proper citation is necessary.
Request for Removal

You can submit a removal request if you own the copyright to this content and don't want it to be available on our website anymore.

Send a Removal Request