Editing Knowledge (section)

== Sources ==
[[File:Five Senses.jpg|thumb|alt=Photos of the five senses|Perception relies on the [[senses]] to acquire knowledge.]]

Sources of knowledge are ways in which people come to know things. They can be understood as cognitive capacities that are exercised when a person acquires new knowledge.<ref>{{multiref | {{harvnb|Kern|2017|pp=[https://books.google.com/books?id=eyh5DQAAQBAJ&pg=PA8 8–10, 133]}} | {{harvnb|Spaulding|2016|pp=[https://books.google.com/books?id=4ct5CwAAQBAJ&pg=PA223 223–224]}} }}</ref> Various sources of knowledge are discussed in the academic literature, often in terms of the mental faculties responsible. They include perception, introspection, memory, inference, and testimony. However, not everyone agrees that all of them actually lead to knowledge. Usually, [[perception]] or observation, i.e. using one of the [[senses]], is identified as the most important source of empirical knowledge.<ref>{{multiref | {{harvnb|Hetherington|2022a|loc=§ 3. Ways of Knowing}} | {{harvnb|Stroll|2023|loc=§ The Origins of Knowledge}} | {{harvnb|O'Brien|2022|loc=Lead Section}} }}</ref> Knowing that a baby is sleeping is observational knowledge if it was caused by a perception of the snoring baby. However, this would not be the case if one learned about this fact through a telephone conversation with one's spouse. Perception comes in different modalities, including [[Visual perception|vision]], [[Auditory perception|sound]], [[touch]], [[Olfactory perception|smell]], and [[taste]], which correspond to different [[Physical stimulation|physical stimuli]].<ref>{{multiref | {{harvnb|Bertelson|Gelder|2004|pp=141–142}} | {{harvnb|Martin|1998|loc=Lead Section}} | {{harvnb|Steup|Neta|2020|loc=§ 5.1 Perception, § 5.5 Testimony}} }}</ref> It is an active process in which sensory signals are selected, organized, and interpreted to form a representation of the environment. This leads in some cases to [[illusion]]s that misrepresent certain aspects of reality, like the [[Müller-Lyer illusion]] and the [[Ponzo illusion]].<ref>{{multiref | {{harvnb|Khatoon|2012|p=[https://books.google.com/books?id=Ha1KBZm9CXQC&pg=PA104 104]}} | {{harvnb|Martin|1998|loc=Lead Section}} }}</ref>

[[Introspection]] is often seen in analogy to perception as a source of knowledge, not of external physical objects, but of internal [[mental states]]. A traditionally common view is that introspection has a special epistemic status by being infallible. According to this position, it is not possible to be mistaken about introspective facts, like whether one is in pain, because there is no difference between appearance and reality. However, this claim has been contested in the contemporary discourse and critics argue that it may be possible, for example, to mistake an unpleasant itch for a pain or to confuse the experience of a slight ellipse for the experience of a circle.<ref>{{harvnb|Steup|Neta|2020|loc=§ 5.2 Introspection}}</ref> Perceptual and introspective knowledge often act as a form of fundamental or basic knowledge. According to some [[Empiricism|empiricists]], they are the only sources of basic knowledge and provide the foundation for all other knowledge.<ref>{{multiref | {{harvnb|Hetherington|2022a|loc=§ 3. Ways of Knowing}} | {{harvnb|Stroll|2023|loc=§ The Origins of Knowledge}} }}</ref>

Memory differs from perception and introspection in that it is not as independent or basic as they are since it depends on other previous experiences.<ref>{{multiref | {{harvnb|Steup|Neta|2020|loc=§ 5.3 Memory}} | {{harvnb|Audi|2002|pp=[https://philpapers.org/rec/AUDTSO-3 72–75]}} }}</ref> The faculty of memory retains knowledge acquired in the past and makes it accessible in the present, as when remembering a past event or a friend's phone number.<ref>{{multiref | {{harvnb|Gardiner|2001|pp=1351–1352}} | {{harvnb|Michaelian|Sutton|2017}} }}</ref> It is generally seen as a reliable source of knowledge. However, it can be deceptive at times nonetheless, either because the original experience was unreliable or because the memory degraded and does not accurately represent the original experience anymore.<ref>{{harvnb|Steup|Neta|2020|loc=§ 5.3 Memory}}</ref>{{efn|[[Confabulation]] is a special type of [[memory error]] that consists remembering events that did not happen, often provoked by an attempt to fill memory gaps.<ref>{{multiref | {{harvnb|Baird|Maskill|2017|p=[https://books.google.com/books?id=6WbgDQAAQBAJ&pg=PA140 140]}} | {{harvnb|AHD Staff|2022e}} }}</ref>}}

Knowledge based on perception, introspection, and memory may give rise to inferential knowledge, which comes about when reasoning is applied to draw inferences from other known facts.<ref>{{multiref | {{harvnb|Hetherington|2022a|loc=§ 3d. Knowing by Thinking-Plus-Observing}} | {{harvnb|Steup|Neta|2020|loc=§ 5.4 Reason}} }}</ref> For example, the perceptual knowledge of a Czech stamp on a postcard may give rise to the inferential knowledge that one's friend is visiting the Czech Republic. This type of knowledge depends on other sources of knowledge responsible for the premises. Some [[Rationalism|rationalists]] argue for rational intuition as a further source of knowledge that does not rely on observation and introspection. They hold for example that some beliefs, like the mathematical belief that 2 + 2 = 4, are justified through pure reason alone.<ref>{{multiref | {{harvnb|Audi|2002|pp=[https://philpapers.org/rec/AUDTSO-3 85, 90–91]}} | {{harvnb|Markie|Folescu|2023|loc=Lead Section, § 1. Introduction}} }}</ref>

[[File:Borochov-testimony.jpg|thumb|alt=Photograph of a person giving testimony|Knowledge by testimony relies on statements given by other people, like the testimony given at a trial.]]
[[Testimony]] is often included as an additional source of knowledge that, unlike the other sources, is not tied to one specific cognitive faculty. Instead, it is based on the idea that one person can come to know a fact because another person talks about this fact. Testimony can happen in numerous ways, like regular speech, a letter, a newspaper, or a [[blog]]. The [[Philosophy of testimony|problem of testimony]] consists in clarifying why and under what circumstances testimony can lead to knowledge. A common response is that it depends on the reliability of the person pronouncing the testimony: only testimony from reliable sources can lead to knowledge.<ref>{{multiref | {{harvnb|Steup|Neta|2020|loc=§ 5.5 Testimony}} | {{harvnb|Leonard|2021|loc=Lead Section, § 1. Reductionism and Non-Reductionism}} | {{harvnb|Green|2022|loc=Lead Section}} }}</ref>