section_path: Central concepts/Knowledge
section_name: Knowledge
paragraph_text: Knowledge
  
  Knowledge is an awareness, familiarity, understanding, or skill. Its various forms all involve a cognitive success through which a person establishes epistemic contact with reality. Knowledge is typically understood as an aspect of individuals, generally as a cognitive mental state that helps them understand, interpret, and interact with the world. While this core sense is of particular interest to epistemologists, the term also has other meanings. Understood on a social level, knowledge is a characteristic of a group of people that share ideas, understanding, or culture in general. The term can also refer to information stored in documents, such as "knowledge housed in the library" or knowledge stored in computers in the form of the knowledge base of an expert system.
  
  Knowledge contrasts with ignorance, which is often simply defined as the absence of knowledge. Knowledge is usually accompanied by ignorance since people rarely have complete knowledge of a field, forcing them to rely on incomplete or uncertain information when making decisions. Even though many forms of ignorance can be mitigated through education and research, there are certain limits to human understanding that are responsible for inevitable ignorance. Some limitations are inherent in the human cognitive faculties themselves, such as the inability to know facts too complex for the human mind to conceive. Others depend on external circumstances when no access to the relevant information exists.
  
  Epistemologists disagree on how much people know, for example, whether fallible beliefs about everyday affairs can amount to knowledge or whether absolute certainty is required. The most stringent position is taken by radical skeptics, who argue that there is no knowledge at all.