2. PHILSOPHY
•Philosophy is a science of the logical foundation
of all knowledge
•It is the first logical science
•Philosophy is the highest generalization which
scientific research suggest
•It consist of great unifying truth, the science of
sciences.
3. PHILOSOPHY
Philosophy is:
(a) the attempt tp acquire knowledge
(b) by rational means
(c) about topics that do not seem amenable to empirical investigation.
Condition
(a) distinguishes philosophy from creative disciplines such as literature or
music
(b) distinguish philosophy from mysticism and some varieties of religion.
(c) distinguishes philosophy from the empirical sciences.
4. THEORY OF KNOWLEDGE
•What is knowledge?
•What are the types of knowledge?
•How do we acquire knowledge?
•What do we know?
•How do we know what we know?
5. THE VISIBLE WORLD
The visible world consists of the things below(main) line in the metaphor of the Divided Line:
physical objects and their images, shadows, and reflections.
Physical objects are constantly changing(in flux, to use the Herecliteen term). They are trensient and
ephemeral.
Physical objects are less real than the Forms. Physical objects get what reality they have by their
participation in the forms.
We learn about physical objects empirically, by means of the senses: we look at them, taste them,
listen to them, and so on. But none of the information we gain in this way is reliable or trustworthy:
we don’t have real knowledge of the visible world, just mere ‘”opinion”.
In a sense, though, knowledge of the forms also enables us to better understand the visible world.
When we understand the Forms, we know what the visible world is a pale imitation of (as the
person who returns to the cave better understands the shadows on the wall by virtue of knowing
what they are shadows of).
The sun is what allows us to see physical objects.
6. THE INTELLIGENT WORLD
The intelligible world consists of the things above the (main) line in the metaphor of the divided
line: image and forms.
The forms are unchanging and eternal
The Forms are what really exists: the physical world is a kind of shadow or reflection of the world of
the forms.
we learn about the forms not by means of the sense but by means of Reason. We don’t need to
look at the forms or listen by thinking about them. Empirical evidence is at best irrelevant, at worst
misleading.
The good what allows us to understand the forms. (This is why the genuinely just person can’t be a
creep. We’re just to extend that our appetites and our reason are both properly developed and
work together harmoniously, But when reason is developed, it makes us aware of the good, and--
Plato thinks -- we can’tknow the good without wanting to do it. So unless we do the good, we will
inevitably be in inner turmol.)
8. WHAT IS KNOWLEDGE
• Knowledge is a “Justified True Belief” (JTB)
S knows that p i and only if:
(1) S believes that p
(2) p is true
(3) S is justified in believing that P
S=Subject
P=Proposition
9. BELIEF
•Belief is the psychological state in
which an individual hol holds
aproposition or premise to be true.
10. TRUTH
•“To say of something which is that it is not,
or to say of something which is not that it is,
is false.
However, to say of something which is
that it is, or of something which is not that is
not, is true,”
11. JUSTIFICATION
•To know that a given proposition is
true
believe the relevent true
proposition
have a good reason for doing so.
12.
13. THE CERTAIN TRUE BELIEF (CTB)
S Knows that p if and only if:
(1) S believes that p
(2)p is true
(3) S is absolutely certain that p
A problem: it seems to lead to skepticism about knowledge, the view
that we can know little or nothing.
14. THE RELIABLE TRUE BELIEF (RTB)
S knows tHat p if and only if
(1) S believes that p
(2) p is true
(3) S’s belief that p is a reliable indicator that
p: in the circumstances S is actually in, S’s
belief that p can be caused only by p.
15. KNOWLEDGE AND SKEPTICISM
•S knows that P if and only if:
P;
S believes that P;
if P were false, S would not believe that
P;
if P is true, S will believe that P
16. EXTERNALISM AND INTERNALISM
• Externalists
• the factors deemed “external”, meaning outside of the
psychological states of those who gain knowledge, can be
conditions of knowledge
• Internalists
• Since the only method by which we perceive the external
world is through our senses, and that, since the senses are
not infallible
• we should not consider our concept of knowledge to be
infallible.
17. HOW DO WE ACQUIRE KNOWLEDGE
• A priori and posteriori knowledge
• Analytics/synthetic distinction
• Specific theories of knowledge acquisition
• Empiicism
• Rationalism
• Construction
• The regress problem
• Response to the regress problem
• infinitism
• Fundationalism
• Coherentism
• Foundherentism
18. A PRIORI AND A POSTERIORI
•A priori knowledge is knowledge that is
known independently of experience
•e.g “Georgr V reigned from 1910 to 1936.”
•A posteriori knowledge is knwledge that is
known by experience
•‘’If George V reigned at all, then he reigned
for at least a day.”
19. ANALYTIC/SYNTHETIC PROPOSITION
•Analytics propositions are those which are
true simply by virtue of their meaning.
•“All bachelors are unmarried.”
•Synthetic propositions, on the other hand,
have distinct subjects and predicates.
•“All triangles have three sides”
20. THEORIES OF KNOWLEDGE ACQUISITION
• Empericism: that knowledge arises from senses
experience
• Rationalism: that knowledge is primarily acquired by
a priori processes or is inmate
• Constructivism: proposes new definitions for
knowledge and truth that form a new paradigm,
based on inter-subjectivity instead of the classical
objectivity, and on viability instead of truth.
21. THE REGRESS PROBLEM
• Assuming that knowledge is justified true belief. Then:
• Suppose that P is some Piece of knowledge. Then P is a justified true
belief.
• The only thing that can justify p is another statement - let’s call it P1;
so P1, justifies P.
• But if P1 is to be a satisfactory justification for P, then we must know
that P1.
• But for P1 to be known, it must also be a justified true belief.
• That justfication will be another statement - let’s call it P3, so P3
justifies P2.
• and so on.
22. RESPONSE TO THE REGRESS PROBLEM
• Infinitism: It is not impossible for an infinite justificatory
series to exist
• Foundationalism: that some beliefs that support other
beliefs do not themselves require justification by other
beliefs
• Coherentism: that an individual belief is justified circularly by
the way it fits together (coheres) with the rest of the belief
system of which it is a part
• Foundherentism: it is meant to be a unification of
foundationalism and coherentism
23. PERCEPTION
• Basic kind of Perception
• Theory of Perception
• Phenomenalism
• Perception and Senses
• Problem of Perceptual knowledge
• Indirect Realism
• Idealism
• Direct Realism
