1. GROUP TWO
WHAT BRANCH OF PHILOSOPHY TRAINS US HOW TO
GET KNOWLEDGE?
WHO ARE THE PHILOSOPHERS BEHIND THAT BRANCH
OF PHILOSOPHY?

2. Epistemology
 Epistemology:
 the theory of knowledge.
 analyzes concepts such as belief, truth, knowledge,
justification and opinion.
 Some epistemological questions include:
What distinguishes knowledge from mere belief?
What can be known with certainty?
How can we know if we have knowledge?

3. Defining Knowledge
 Knowledge: is often contrasted with mere opinion or mere
belief.
 Beliefs without knowledge: But knowledge is more than
just belief for I can have beliefs about all sorts of things
without knowing them.
 True Belief: so for a belief to count as knowledge the belief
must be true.

4. More replies to Gettier
 Accepting the counterexamples: We might also reply to
Gettier by accepting his counterexamples to the traditional
definition of knowledge.
 Finding another analysis: In this case we are then out to
find a more adequate analysis of KNOWLEDGE.
 Some examples:
Infallible justification
No false steps
No defeaters

5. Knowledge and justification
 Knowledge: is also more than mere true belief.
 True Beliefs: In order to know that a given proposition is
true, one must not only believe the relevant true
proposition but, also have justification for doing so.
 Justification: involves the reasons why someone holds a
belief based on current evidence.
Justification is a property of beliefs in so far as they are
held blamelessly.
In other words, a justified belief is a belief that a person is
entitled to hold.

6. Knowledge as JTB
 Knowledge as JTB: we might try to define knowledge as justified true belief then.
 For example, S knows p if and only if:
 S believes that p is…
and
 P is true and
 S’s belief that p is justified
 Individually Necessary: Each of these three conditions is necessary for S to know
P.
 Jointly sufficient: together the 3 conditions are jointly sufficient for S to know P.

7. Example of Philosophers of Epistemology
Prof. Gettier and his approach to Knowledge
 Edmund Gettier
 Born in 1927
 Philosophy professor at University of Massachusetts Amherst
since 1967
 In his article Is Justified True Belief Knowledge? Gettier
argues that something’s being justified true belief, is not a
sufficient condition for it’s being knowledge.
 Thus, he argues that one can have a justified true belief and
yet not have knowledge.
 Gettier provides two counterexamples to prove his point.

8. Review
 The Tripartite Analysis: S knows that p iff S has a
justified, true belief that p.
 The Knowledge Thesis: In order to know that
something is the case, you first have to rule out all the
alternatives.
 The Fallabilist Reply: Knowledge is justified true
belief and justification does not require certainty, so
knowledge doesn’t require certainty either.

9. Replies to Gettier
 First Proposal: S knows that there is p if
i. p is true,
ii. S believes that p;
iii. S’s belief that p is justified; and
iv. S is certain that p.

10. Replies to Gettier
 Second Proposal: S knows that there is p if
i. p is true,
ii. S believes that p;
iii. S’s belief that p is justified; and
iv. S’s justification for p does not involve any false
beliefs.

11. Replies to Gettier
 D is a defeater for S’s belief that there is P if were S to
find out about D, he would no longer believe that p.
 Third Proposal: S knows that P if
i. p is true,
ii. S believes that p;
iii. S’s belief that p is justified; and
iv. There is no defeater for S’s belief that p.

12. Smith, the job & 10 coins
 Smith, the job & 10 coins:
 Smith believes that Jones is the man who will get the job and Jones
has 10 coins in his pocket.
 What is Smith’s justification for this belief?
 So Smith infers that it is true that The man who will get the job has
ten coins in his pocket.
 What is Smith’s justification for this belief?
 But Smith gets the job & he has 10 coins in his pocket
 So Smith has JTB without knowledge!

13. The Ford & Barcelona
 Now Smith gains evidence for the proposition:
 That Jones owns a Ford (‘F’)
 What’s Smith’s justification for this belief
 So Smith Infers: Either Jones owns a Ford or Brown is in Barcelona.
(‘A’)
 What is Smith’s justification for this belief?
 But Jones doesn’t own a Ford and Brown is in Barcelona
 So Smith has JTB without knowledge again

14. Replies to Gettier
 Denying the assumptions:
 He assumes that:
 1. It is possible for a person to be justified in believing a
proposition that is false
 2. Closure: for any proposition P, if S is justified in believing P
and
 P entails Q &
 S deduces Q from P &
 S accepts Q as a result of this deduction, then
 S is justified in believing Q.
 Example:
 If it is Snowing then it is Freezing

15. Denying Closure
 Denying closure:
 We could deny Closure by holding an Externalist theory of
justification.
 For the Externalist, justification comes not from an inner mental
state at all. Instead, it is something external to your mind which
confers justification on a belief.
 An Example:
 Reliabilism: a belief is justified if it is formed through a reliable
belief forming process

16. More replies to Gettier
 Accepting the counterexamples: We might also reply to
Gettier by accepting his counterexamples to the traditional
definition of knowledge.
 Finding another analysis: In this case we are then out to
find a more adequate analysis of KNOWLEDGE.
 Some examples:
Infallible justification
No false steps
No defeaters

17. More replies to Gettier
 JT account holds that knowledge is equivalent to justified
true belief… If all three conditions (JTB) are met of a given
claim, then we have knowledge of that claim.

18. More replies to Gettier
Descartes
 Holds an internalist account requiring that all justifying
factors take the forms of ideas.

19. Last thoughts on defining knowledge
 What Gettier shows is that there is a bigger problem with
conceptual analysis
 A possible reply:
 concepts like knowledge have a graded nature

20. Philosophers of Epistemology
 St. Aquinas Thomas (1224 to march 07th/1274)
Was a priest and a licensed lecturer at Dominican schools
incorporated in the university of paris.
John Duns Scotus. He was a catholic priest and Franciscan Friar,
university philosopher and theologian. He was born in Duns UK
Aristotle
Piaget