1. Modern Philosophers
Rationalists Empiricists
– Descartes – Locke
– Spinoza – Berkeley
– Leibniz – Hume
Epistemology - the theory of knowledge (what
and how we know)
2. Epistemology
Epistemology is one of the core areas of philosophy. It
is concerned with the nature, sources and limits of
knowledge. Epistemology has been primarily
concerned with propositional knowledge, that
is, knowledge that such-and-such is true, rather than
other forms of knowledge, for example, knowledge
how to such-and-such. There is a vast array of views
about propositional knowledge, but one virtually
universal presupposition is that knowledge is true
belief, but not mere true belief. For example, lucky
guesses or true beliefs resulting from wishful thinking
are not knowledge. Thus, a central question in
epistemology is: How do we know what we know is
true, and what is the difference(s) between
knowledge, belief and truth?
5. Rene Descartes
Rationalist fixated on figuring out how to
know truth.
Through deconstruction/reduction, he
eliminates everything to get to a
CRITERION OF TRUTH – a kernel of
absolutely true knowledge from which
an entire world can be constructed
6. Phases
Doubt EVERYTHING that can be
doubted
Find the criterion of truth
Expand from that point to find what is
knowable and true
This is a rational exercise – the senses
cannot be trusted.
7. David Hume
Empiricist
– Believes all knowledge comes through
experimentation and observation or
experience of the world
– When we are born, we are “Tabula Rasa”
• Locke coins the term, Hume refines it
8. Hume’s Method
First we experience IMPRESSIONS
– Ideas form, which are fainter copies of
impressions
– Psychology now calls these impressions “Sense
Data”
– Both impressions and ideas can be simple or
complex.
• Simple = individual traits
• Complex = of the whole
THE MIND HAS THE ABILITY TO CREATE
9. Examples
Hume claims we have angels and a
God because of the “cut and paste”
method the mind employs.
By breaking down to simple ideas, then
original impressions, we can know that
our ideas to correspond to reality and
not just make believe.
Hume is a skeptical Agnostic.
10. Hume deconstructs Descartes
God is an infinite, perfect being. Omniscient
and Omnipotent.
• Descartes
No one has experienced infinity, it is
imaginary.
Perfection cannot even be defined for
everybody. We focus on limited, imperfect
reality and remove realistic constraints.
11. Where Hume succeeded
Found Descartes’ subjectivity and biases,
then tore them apart.
We want God and heaven because there is a
psychological need or an indoctrination that
has not been analyzed.
Hume did not believe in cause in effect.
– Something did something, causing something
else.
We are perceiving “constant conjunction”; we
see a sequence of events.
12. EXERCISE
"IF A TREE FALLS IN THE FOREST AND NO ONE
IS AROUND, IS THERE SOUND?"
– Upon what philosophical assumption does the question
depend?
– What should you do next?
– What does the phrase "I never heard of that before" really
mean?
– As you read these words, do you know what else I am
doing?
• What does that imply?
Solve the riddle, and you have a "major" clue to the
novel's progression.
13. Berkeley
Also an empiricist, but is an immaterialist or
idealist.
Material substance does not exist; all that
exists is spiritual (minds and ideas)
God is an infinite spirit, humans are finite
spirits.
Says we cannot perceive tangible
reality, everything perceived is in our mind.
We all DIRECTLY perceive ideas in our
mind, and what we perceive is reality.
14. THEREFORE - what is real is only
ideas and minds.
The material world is the same as our
reality, but on a higher plane. All
material objects are ideas in God’s mind
This answers the first cause of how God
can create a world out of nothing, but
not how God came about.
15. Immanuel Kant
Synthesized rationalism and empiricism
– Said both are partly right and partly wrong, took
the “right” parts from each
All knowledge comes from experience, but
reason determines how we perceive reality.
We need to keep in mind HUMAN
PERCEPTION - a “think in itself” vs. a “thing
for us”
We cannot evade our humanistic filter
16. Disagrees with Hume on causation and
says that is the rational structure of the
mind at work. We apply meaning.
Kant’s ETHICS - based on the
“Categorical Imperative”
– ACT AS IF THE MAXIM OF YOUR
ACTION, THROUGH YOUR WILL,
WOULD BECOME THE LAW OF
NATURE”
17. IN OTHER WORDS: if I did
something, would I want this action to
become the universal standard action
for everyone else in my position, every
time?
This is a call to leave the INDIVIDUAL
perspective and to use the UNIVERSAL
perspective.
