David Hume
An Enquiry concerning Human
Understanding
Quick Quiz
1. Where was Hume born?
2. Where did he get his degree?
3. What is the enquiry basically a summary of?
4. What is empiricism?
5. What is Liberty?
6. What does he mean by Naturalistic?
7. Name two Rationalist philosophers.
8. Hume was trying to find a science of _____?
9. Who was he trying to copy in doing so?
10. What did he disagree with the Greeks about?
Hume’s mission
Hume’s mission was to apply the scientific
method to the human mind
To discover how we acquire knowledge,
and how the mind works
This was to be based on introspection and
by observing others.
He wanted to avoid just ‘making up’
theories without being able to ground
them in fact or experience.
Task
1. Imagine what you are wearing
2. Imagine what your bedroom looks like
3. Imagine what The North Pole is like
4. Imagine what the surface of Mars looks like
5. Imagine what a planet in the next galaxy looks
like
6. Imagine what the universe was like before time
began
Now write down the difference between the
quality of these ideas, and the clarity with which
you have the. What do you notice about them as
you go up the list?
What is it?
What effect does gravity have on
things? (ie what does it do?)
Now write a sentence describing
what gravity IS?
Do you have any problems with
either task?
How far can he go?
Hume admits that there may be
limits to how far he can go in
penetrating how the mind works
That limit is set by experience
Like Newton and gravity- he
couldn’t explain what it was, just
what it did.
Hume’s Philosophy
EMPIRICISM
Other famous empiricists:
John Locke
Bishop Berkeley
Together they were….the British
Empiricists!
Empiricism
Rejection of Innate Ideas
All ideas come from one single
source: EXPERIENCE
Innate Ideas
These are ideas that we are born
with, that we know without any
experience
Examples: Mathematics
Causality
God
I exist
All of these can be argued of course
Introduction
So far we have seen that, although
empiricists claim that we gain all our
knowledge through the senses, there
appears to be a large part of our thinking
that does NOT come about this way
Understanding
Judgement, etc
Before we can understand any idea at all,
we first of all INTERPRET it in some way
Example
When two artists paint the same
scene they do it completely
differently
When A racist man and a non racist
man see a fight they might draw
totally different conclusions about it
Mathematics as an INNATE idea
Descartes, the famous
rationalist, believed that
maths was an innate
idea (or a collection of
ideas)
The Sun looks like it is
very small, but we know
that it is vast. How?
Through science, and
maths
Maths is the language of the world
Many scientists like Galileo
believed that everything in
the world could be broken
down into numbers and
equations
How? When I describe
anything in the world, I can
give it a set of numbers that
refer to it
Height; weight; dimensions,
location etc
Then, when I describe anything
it does, I can break that down
too into numbers and formula
that describe the action
Force=Mass X Acceleration
(F=MA)
Energy= Mass X the speed of
light, squared (E=Mc2)
So mathematics is the ‘language’
of reality
How is this innate?
Because we do not rely on the
evidence of our senses to tell that
1+1=2. It is something that can be
understood purely mentally, without
ever having observed anything
(warning: that last bit is
controversial)
Maths is A priori knowledge, and it
is innate
To quote a famous Greek philosopher
‘Even a slave can tell me that the
area of a semicircle is half that of a
circle, with no formal training in
maths.’
The Wax
example
Descartes famously
described this using
the example of a
piece of wax
If I take a piece of
wax and heat it
It changes shape;
smell; taste; colour;
sound and feel.
Basically every sense
experience is
different about it
now. So how do I
know it is the same
piece of wax?
Innate knowledge
I know it innately. I have an
understanding of the ‘concept’
of wax that does not rely on
any sense experience of the
wax itself.
Therefore I know what wax
really is, despite the evidence
of the senses.
And what is it? Descartes says
it is EXTENSION in space. And
this can be expressed
mathematically. NUMBERS!!
Simple.
Tabula Rasa
This means ‘white paper’, and is the idea
that we are born with a ‘blank slate’
mind, nothing in it.
Then as we go through life, we get ideas
‘written’ on it by experiences gained
through the senses.
This view is held by John Locke and David
Hume
John Locke
Let us then suppose the mind to be, as we say,
white paper, void of all characters, without any
ideas. How does it come to be furnished? From
where does it come by that vast store which
the busy and boundless fancy of man has painted
on it with an almost endless variety? From
where does it have all the materials of reason and
knowledge? To this I answer, in one word,
from experience.”
David Hume
He argued that our ideas are like copies
of the things we experience in the real
world
He argues this by saying that a blind man
has no idea about what ‘red’ is until he
has his sight restored.
Therefore we cannot imagine things like
‘red’ until we experience it.
Therefore the mind is a blank slate,
written on by experience.
Task
In a moment you will be shown a picture
for five seconds
Each of you will have to look at the screen
and see how much you can remember
from the picture
Then you will have thirty seconds to
recreate the picture on your own paper
We will do this three times
How much will you get?
How did you do?
This exercise shows that the images
we experience through our senses
are MUCH more distinct, sharp,
powerful than the ones we hold in
our minds alone
Any problems with this?
Are there any ideas we have in our
heads that could not have come
from the real world?
List three examples
A golden mountain
A unicorn
A mermaid
Hume’s response
No problem; these ideas are made up of
‘bits’ of things we have seen
We’ve seen a fish. We’ve seen a lady.
Voila! Put them together and we have a
mermaid.
Hume would say we have taken two
SIMPLE ideas and made up a COMPLEX
one from them, like a house is made up
out of building blocks.
Hume’s STRONG claim
Hume says that ONLY ideas from the
world of the senses can be formed in the
mind.
We call this Hume’s STRONG claim. That
our minds are TOTALLY blank until we
experience something
He says that although it seems we can
imagine anything at all, in reality we can
only imagine things that are made up of
things we have experienced.
Hume’s next claim
All of our mental ideas are much
weaker than experiences of the
senses (sensations), as we have
seen.
It is very hard to be ‘fooled’ by
sensations, as they are so clear,
vivid and precise
Mental ideas on the other hand are
vague and imprecise. We often
make mistakes.
Task
Close your eyes and imagine what
Barack Obama looks like
Furthermore…
If an idea in your head (like a word)
doesn’t relate directly to a
sensation, then it is MEANINGLESS
Like a Fjhguyt. Or a UIGYGIk. These
are meaningless ideas.
Other meaningless ideas….
‘A time before time’
‘Infinity’
‘An immovable object.’
‘An irresistible force.’
Although these words SEEM to make sense, Hume
would say that they do not. We have NEVER
experienced them, so we have nothing to refer to.
So any philosophy that talks about
such concepts is just illusion and
sophistry (a tricky, false argument
that sounds good.)
Hume’s method
Now we can distinguish between
ideas that make sense and ideas
that don’t
Now we have a method to clarify
ideas- see if they relate to
something perceptible, then go an
perceive it!
Empiricists
Hume and Locke are often called
Empiricists (from the Greek word
empeira, meaning ‘experience’)
This means that experience is the basis of
all our ideas and thoughts.
Our brains are like old fashioned
photographic film- empty of any image
until exposed to light (or experience of
any kind)