Knowledge is an awareness of facts, a familiarity with individuals and situations, or a practical skill. Knowledge of facts, also called propositional knowledge, is often characterized as true belief that is distinct from opinion or guesswork by virtue of justification. While there is wide agreement among philosophers that propositional knowledge is a form of true belief, many controversies focus on justification. This includes questions like how to understand justification, whether it is needed at all, and whether something else besides it is needed. These controversies intensified in the latter half of the 20th century due to a series of thought experiments called Gettier cases that provoked alternative definitions.
The owl of Athena, a symbol of knowledge in the Western world
Declarative knowledge can be stored in books.
Knowing how to ride a bicycle is one form of non-propositional knowledge.
Perception relies on the senses to acquire knowledge.
Declarative knowledge is an awareness of facts that can be expressed using declarative sentences. It is also called theoretical knowledge, descriptive knowledge, propositional knowledge, and knowledge-that. It is not restricted to one specific use or purpose and can be stored in books or on computers.
Declarative knowledge can be expressed using declarative sentences stored in books.
The thought experiments by Edmund Gettier influenced many epistemologists to seek additional components of declarative knowledge.
Knowing how to play the guitar is one form of non-declarative knowledge.
Familiarity with the flavor of chocolate is one example of knowledge by acquaintance, which belongs to non-declarative knowledge.
