Subjects can know {knowledge}.
types
Knowledge can be skills, acquaintances, and propositions. Machines, animals, and people can know skills. Animals and people can know acquaintances. People can know propositions.
types: knowing
Knowledge can mean knowing all parts and relations. It can mean ability to express in words. It can mean ability to express in syllogisms or other logical forms and to know reason relations.
topics
Knowledge can be mental states that relate to external objects and events. Knowledge can self-relate and so be true in itself. Knowledge can be about abstract Forms, Ideas, essences, unchanging things, truth, true beliefs, or reasonable beliefs.
requirements
Knowledge can require truth, justification, and/or belief. Perhaps, subjects cannot know false propositions, because they do not exist. Subjects can justify or not justify beliefs. Subjects can believe or not believe propositions. To have knowledge, instead of just beliefs, requires concepts.
sources
Knowledge and belief sources are sense qualities, memories, reasoning, and introspections.
feeling
People know if they have knowledge, even if they do not remember facts. People know if they know meaning, even if they cannot make synonyms or define words. People know if they have seen or heard something before, even if they do not remember it. People know if they have found correct answer and feel that something is not right if they have close answers. People feel that they know something, even if they do not know relations or connections. People know contexts of things learned or experienced.
factors: subjectivity
Emotion, body, subjectivity, and personal experience can determine human knowledge.
factors: cultural background
All knowledge has social and cultural backgrounds. Knowledge depends on reference frames.
perception
People can perceive without knowing {thing-perception, knowledge} or can know perception facts {fact-perception, knowledge}. Percept can know sense qualities {proximal stimulus} and transform them to percepts {distal stimulus}. Experience correlates with physical quantities [BonJour, 1985].
perception: illusion
People cannot base knowledge on perception, because senses have illusions. All observers agree on illusory perceptions, but all are wrong.
memory
To verify facts about past, current experience must relate to past. Understanding the past requires evidence. Evidence about past times decrease over time.
Perhaps, first-person present-tense beliefs about consciousness contents are infallible {Cartesian intuition} [Dennett, 1991].
People learn from empirical observation {certainty} {certum}. However, people use mental models to interpret sensory experience.
If people know p and p entails q, then people know q {knowledge under entailment}. Knowledge closure can occur under entailment.
If people know p and know that p entails q, then people know q {knowledge under known entailment}. Knowledge closure can occur under known entailment.
Knowledge needs justification {justification, knowledge}. Justification is about probable beliefs. Justification does not allow chance truth. Beliefs must match relevant evidence and/or use valid methods. Justification cannot use incorrect reasoning/cognition and cannot use incorrect facts or ignore facts. Evidence and methods can be internal, such as introspections, mental states, or cognitive processes, or external, such as objective reliability tests.
Beliefs can have true evidence {evidentialism}, known by subjects. Evidence comes from perception, introspection, memory, and reasoning.
Reliable methods can justify beliefs {reliabilism}. Beliefs can have valid knowing methods used by subjects. Methods can be perception, introspection, memory, and reasoning. Reliable methods can be their own justification or require further knowledge. Sensory and perceptual beliefs co-vary with external world, based on perceptual abilities, and so can have justification.
Knowledge is not always justified true belief, because belief can be true and justified but not knowledge {Gettier problem} [1963: Edmund Gettier]. Justification applies to first object, but truth applies to second object. First object can mistakenly seem to be second object.
case
Justified and true beliefs {Gettier-case} are not sufficient for subjects to know propositions. People can believe true and justified probabilistic statements but not know statement instances. On movie sets, all but one house can be façades, and people not knowing this can look at the real house and state their belief that it is a house. This proposition is true but only by chance. If people do know almost all houses are facades, people state their belief that main house is also not a house.
Knowledge {metaknowledge} about knowledge aids memory and learning.
Knowledge {metempiric knowledge} can be outside or beyond experience or experiment.
Media can store declarative knowledge {objective knowledge}. If knowledge is only what people understand, there is no objective knowledge. Subjective knowledge differs from objective knowledge, so experience does not relate to objective knowledge.
Non-conscious knowledge {tacit knowledge} can produce behavior and mental states.
People can gain knowledge only by experience, perceptions, introspections, and certain memory types {knowledge by acquaintance}.
Knowledge can be communicable by language {knowledge by description}.
Knowledge {declarative knowledge} can be about propositions, facts, and concepts. Structural descriptions recognize. Functional descriptions connect structures and functions for action. Declarative knowledge can be for imagination, planning, and other cognitive functions. Perhaps, procedural memory and knowledge evolve to allow kinesthetic perceptions, vestibular, and touch perceptions. Perception becomes possible because brain evolves to detect, use, and remember procedure components or units.
Knowledge {procedural knowledge} can be about knowing how to do something.
Outline of Knowledge Database Home Page
Description of Outline of Knowledge Database
Date Modified: 2022.0225