Knowledge

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Key concepts of belief and knowledge

Definition of an assertion and proposition

Assertion: a linguistic act, spoken or written, that has truth value

Truth value: state of being true, false or indeterminate. All declarative sentences have truth values, and those that declare sth about the past are either true or false. Future indeterminate.

Questions do not assert anything

Proposition: content of assertion, underlying meaning of what you are saying. Assertions change if said in different languages.

Proposition is true if it asserts a claim that corresponds to reality. Eg: This is a cat. if object referred to is a cat, proposition is true; otherwise false.

Belief is propositional attitude

Propositional attitude: a speaker's mental attitude towards their propositions. Either " of disbelief or " of belief.

Belief: propositional attitude of truth. In other words, propositional attitude determines whether one holds a belief. Beliefs can be false, as thinking sth does not correspond to reality does not equal truth

Forms of justification

Traditional definition of knowledge: Justified true belief. Eg: This is a cat

(belief) I must believe that there is a cat

(true) It is indeed a cat

(justified) evidence to support that it is a cat, such as looks, feel. Testimony (taking someone's word on it), eg experts such as books and teachers. First-person observation works too. Justification: support/ evidence for beliefs.

Justification: support/evidence for beliefs

Traditionally agreed upon bc belief must be supported by evidence, and it must be true. Can have false belief, but not false knowledge. And if sth we believed turned out to be false, then it is a false belief.

Also if you have a belief without justification, but just lucked into being right, it is not knowledge as well

Gettier cases:

Cases where justified true belief, but not knowledge

Case 1: See a shape on the field, looks like a sheep, assume it is sheep, and then declare "There is a sheep in the field". However, shape is actually a dog, so we are wrong. BUT on the other side of the hill, there is a sheep just obscured by the hill.

Case of being "lucked into" knowledge, thus not true knowledge.