Knowledge and Assertion I
Assertion is a speech act in which something is
presented as true There are infinitely many
prime numbers, There is traffic congestion on
Assertion is the speech act that goes toge
Theorising About Justification
What Is the Core Epistemic Notion?
Until now we have been interested in
epistemic justification only in so far as it sheds
light upon the nature of knowledge.
For many, though, epistemic justif
Introducing the Regress Problem
Many of the justified beliefs that we hold seem to be justified in
virtue of further justified beliefs that we hold.
In many cases, ones justification for holding a certa
The Closure of Knowledge
Closure of knowledge: If S knows that P
and P entails Q and S competently
deduces Q from P then S knows that Q.
Surely deduction, if anything, is an
epistemically safe way of extending ones
Theorising About Knowledge
Four senses of knows
Propositional knowledge or knowledge-that.
John knows that the sky is blue.
Acquaintance knowledge. John knows the
Knowledge-how. John knows how to change a
Knowledge and Stakes
Knowledge is a context sensitive term it picks
out different epistemic properties in different
contexts of use or attribution.
S knows that P may be true when uttered in a
Knowledge and Assertion II
Recap: Problems for the Knowledge
The knowledge account seems unduly harsh.
What about justified but false beliefs? Snow case: Its
a cold winter morning and the forecast was for snow.
In order to know that a proposition P is
true, one must have ruled out or
eliminated all possible situations in which
P is false.
The Theory of Relevant
In order to know
Recap: The Sceptical Argument
(i) You are in no position to know that you are not a brain
in a vat.
(ii) If you know that you have hands then you would be in
a position to know that you are not a brai
The Gettier Problem
Recap: The Tripartite Account
S knows that P iff
(i) S believes that P
(ii) P is true
(iii) S is justified in believing that P
Coins example: I have very good evidence to think tha