Defining Knowledge

Real essence

Can be given a real defintion

Nominal essence

No real definition possible

Plato’s tripartite knowledge

A subject knows that a proposition is true if and only if a subject believes that the proposition is true, the proposition is true, and the subject's belief that the proposition is true is justified.

Infallibilism

A subject knows a proposition is true if and only if the subject believes that the proposition is true, the proposition is true and the subject’s belief is infallibly justified (the proposition is indubitable).

No false lemmas

A subject knows a proposition is true if and only if the subject believes that the proposition is true, the proposition is true, the subject’s belief in is justified and that the subject’s belief is not based on a false lemma.

Reliabilism

A subject knows a proposition is true if and only if the subject believes that the proposition is true, the proposition is true and the subject’s belief is produced by a reliable cognitive process.

A reliable cognitive process

A process that produces a higher proportion of true beliefs than false beliefs.

Generality problem

This issue asks which specific mental process we should examine to judge whether a belief is reliable. A single belief can be explained in different ways - either by looking at a broad thinking pattern (like perception or memory in general) or a narrower, more specific one (like noticing something in dim light or remembering something under stress). Depending on which level we choose, our evaluation of the belief’s reliability could change.

Aristotle’s epistemic virtues

A subject knows a proposition is true if and only if the subject believes that the proposition is true, the proposition is true and the subject’s belief results from exercising epistemic virtues.

Epistemic virtue

Particular skills, abilities or traits that contribute to someone getting to the truth. They are the processes and qualities that are more likely to yield a higher rate of true belief.

Sosa’s AAA Knowledge

Knowledge requires accuracy, adroitness and aptness. Accuracy: is the belief true? Adroitness: did the person form their belief by using their epistemic virtues? Aptness: is the belief true because they formed it by using their epistemic virtues?

The barn problem

A problem which challenges Triple-A knowledge by showing a belief can be accurate, adroit, and apt but not knowledge. It portrays a situation where there is a field of what appears to be barns and you point at one and declare it a barn. Unknown to you, this area is full of fake barn facades - realistic-looking structures that aren’t actually barns. The one you pointed at just happens to be the only real one. This is accurate because it is true, adroit because you used epistemic virtues of sight and recognition and apt because you believe it because of the use of those virtues. But can this be considered knowledge?