Propositional knowledge
Introduction
Propositional knowledge, also known as "declarative" or "descriptive" knowledge, is a type of knowledge that can be expressed in declarative sentences or indicative propositions. It is the knowledge of "what is" - the facts, information, or descriptions that we can articulate, write down, or communicate to others. This form of knowledge contrasts with other types, such as procedural knowledge, which involves knowing "how to" perform certain tasks or activities.
Nature of Propositional Knowledge
Propositional knowledge is typically expressed in the form of propositions, which are statements that declare something to be the case. These propositions can be either true or false, and their truth or falsity can be determined independently of the person who holds the knowledge. For instance, the proposition "Paris is the capital of France" is true regardless of whether anyone believes it or not.
Propositional knowledge is often contrasted with tacit knowledge, which is knowledge that is difficult to articulate or express in propositional form. Tacit knowledge is often acquired through experience and is typically used unconsciously, such as the knowledge used to ride a bicycle or play a musical instrument.
Epistemology of Propositional Knowledge
In epistemology, the study of knowledge and belief, propositional knowledge is often defined as justified true belief. This definition, known as the "JTB" account, holds that for a person to know a proposition, three conditions must be met: the proposition must be true, the person must believe the proposition, and the person must have adequate justification for believing the proposition.
However, the JTB account of knowledge has been challenged by various philosophical arguments, most notably the Gettier problems, which present scenarios in which the three conditions are met but where it seems incorrect to say that the person has knowledge. These problems have led to numerous attempts to refine or replace the JTB account of knowledge.
Propositional Knowledge in Cognitive Science
In cognitive science, propositional knowledge is often associated with the concept of semantic memory, which is the memory of facts and general knowledge about the world. This contrasts with episodic memory, which is the memory of specific events or experiences.
Cognitive scientists study propositional knowledge to understand how it is acquired, stored, and retrieved in the brain. This research has implications for a range of fields, including artificial intelligence, education, and neuropsychology.
Propositional Knowledge in Artificial Intelligence
In the field of artificial intelligence, propositional knowledge is often represented using formal languages, such as first-order logic. These languages allow for the representation of complex knowledge structures and the performance of logical reasoning.
Artificial intelligence systems often use propositional knowledge to make decisions, solve problems, and understand natural language. For example, an AI system might use propositional knowledge to understand the meaning of a sentence, to plan a sequence of actions, or to infer new knowledge from existing knowledge.