Knowing and knowing that we know

Derek Matravers

The ‘KK principle’

• If one knows that p, one knows that one knows that p.

• KK: If I believe there is a lamp on the table, I believe I believe that there is a lamp on the table.

• KK is false.• Call the belief that there is a lamp on the table, ‘belief 1’.

• Call the belief that I believe there is a lamp on the table, ‘belief 2’.

• The KK principle says that I cannot have belief 1 without belief 2.

• However, I cannot have belief 2 without some further belief – belief 3 (that I believe that I believe I believe there is a lamp on the table …)

• The regress is infinite.

What follows?

• I can know something without knowing that I know it.

• If I cannot say how I know something, it does not follow that I don’t know it.

• That is, if someone cannot answer the question ‘How do you know that?’, they are not necessarily in trouble.

Externalism

Belief that there is a

lamp on the table

Reliable belief-forming mechanisms

• What we need are mechanisms that are reliable formers of belief.

• The eye is one such mechanism.

• Do we need to know it is reliable?

• No – that would be to accept the KK principle

• And, knowing that it is reliable would make no difference to what matters: namely, whether or not it is reliable.

• Thanks for listening!