Transcript Empiricism PowerPoint

An Adventure into the land of...
Empiricism
Starring:
The 3 Anchor Points of Empiricism:
1. The only sense of genuine knowledge is sense
experience (ie. What you touch, taste, hear, smell, see).
2. Reason is an unreliable and inadequate route to
Knowledge unless it is grounded in the solid foundation of
sense experience.
3. There is no evidence of innate ideas within the mind that
are known apart from experience.
What shortcomings exist in viewing perception
as such a simple 2-way street?
The Tabula Rasa
The notion of innate ideas (ie. Rationalism), as we have already seen, presupposes that certain knowledge is
present from birth. This is different to saying that some types of knowledge are a priori (or true by definition).
Empiricists would not want to deny, for example, that "All bachelors are unmarried" is a truth independent of
experience. They would, however, deny that such a truth could be innate.
For the Empiricists, the mind is a Tabula Rasa (which is Latin for "blank slate"). When we learn or experience
things, it is as if the mind is being written on. For the Rationalists, however, the mind is like a computer: the
hardware already has some functions (innate ideas) before the software (experiences, specific knowledge) is
loaded.
The new Will Farrell full of
knowing
knowledg
e
Hi, kids!
Through experience we “fill”
our heads with knowledge
Question:
If innate ideas don't exist, is it possible to learn anything)?
Awesome
Ramp
Simple ideas:
The Empiricists want to argue that all our ideas come from experience. So, how do we understand the world?
Locke thought that our experiences provided us with what he termed simple and complex ideas. Simple ideas
might include the redness of a rose, the smell of coffee, the taste of sugar or the sensation of heat. We
thereafter use these ideas as the basis for reflection, combining and comparing them to form complex ideas in
order to understand the world.
An example of this can be seen in the way we might get a better understanding of heat. I might burn
my hand on a flame, but also on an extremely cold piece of ice. Reflecting on this and other examples
I may come to the conclusion that it is not heat which is solely responsible for burns, but difference in
temperature (in this case, the difference between my hand and the hot and cold things). Thus, the
simple sensations and experiences form the basis for more abstract ideas such as this.
The Taco Bell nachos are red...
and green...and yellow...
and warm...and spicy...some are crispy...
some are soft...and salty smelling...
Hwhy hwouldn't you eat such hwonderfuly
tasty nachos? Hwhat in the hworld is
stopping you?
Taco Bell nachos
Exercise:
Pick 3 objects in the room you are in and list five simple ideas about them. Once you have done this,
see what complex ideas each of the simple ones might help you form.
Primary and Secondary Qualities
If we reject, as the Empiricists do, the idea that all our knowledge comes from rational principles, we are left
with a major question: How can we tell which of our perceptions are real or true? Locke's answer is to suggest
the existence of what he calls primary and secondary qualities.
First of all, let us consider an object - a table, for example. Now, Locke's view is that certain qualities of the
table are primary qualities of the object (such as the table's shape and size), but others are produced by
powers in the object itself, which act on our senses to produce sensations and impressions. Such things as
colour, taste and temperature are therefore secondary whilst other primary qualities include number (how
many objects there are) and motion (an object's speed or movement).
The main thing Locke was trying to do is to limit knowledge to the things that could be said to be primary
qualities. So, as far as the table is concerned, such things as its size, shape and weight are fixed and
measurable. Its colour, on the other hand, is a matter of subjective opinion.
Exercise
Of the simple and complex ideas you listed in the previous example, which are primary and which are
secondary? Go through your lists and mark P or S next to each one.
Thought Experiment:
1. Have you found that the perceived color of a piece of clothing changes when you view it
by the light of a lightbulb, a neon light, semidarkness, or sunlight? For example, have you
ever thought that you were putting on matching socks only to find when you stepped outside
that one was black and one was blue?
2. Why doesn't the shape, size, or motion of an object appear to change in different
lights?
3. Have you ever disagreed with a friend as to whether the room is too hot or the iced tea
too sweet? Why doesn't it make sense to say one of you is right and the other is
mistaken?
4. Hold a cut, raw onion under your nose as you bite into an apple. Does the normal taste of
the apple appear to be different under these circumstances?
These thought experiments illustrate the fact that
some properties, such as size, shape, or motion,
are constant, whereas other properties, such
as color, temperature, or taste, can change from
one circumstance to the next.
Empirical Knowledge
Locke considered that knowledge could be of certain types depending on how ideas could be compared. The
idea of black, for instance, could be contrasted with that of white; other ideas seem to share a common source,
such as light and fire, which quite often go together. These ways of building up information, Locke thought, are
the main means by which we turn simple ideas into complex ones.
But how certain is such knowledge? Locke considered that there are 3 main types of knowledge:
Intuitive. This form of knowledge is the most certain because it seems the most obvious to us and the
most difficult to doubt. This would be such things as "I have a body", "Black is not white", but also according to Locke - "God exists". These are so obvious that we accept them intuitively.
Demonstrative. When we begin to put simple ideas together to form complex ones, we are
demonstrating something. So, for example, if I compare the heat of the Sun with the heat of a fire, I
may demonstrate that they are both made of similar substances.
Sensitive. This form of knowledge is the most uncertain because it relies merely on the evidence of the
senses. If I look to see how many chairs there are in another room, I am relying on sensitive
knowledge, which - as Descartes has shown - can, in some cases, be mistaken.
I do believe this
is a most capital
idea! I particularly
rule.
Thought Experiment:
How would Locke give an empirical account of the origin of the following ideas by
compounding, relating, and abstracting from the ideas formed through experience:
1. Infinity
2. God
4) Me. Seth Rogen.
3. Moral goodness or evil My awesomeness. How do you know
what my awesomeness is?
Berkley and Idealism
Locke's concept of primary and secondary qualities, whilst intended to help us make sense of the limits of
knowledge, also had an unintended use. Locke had argued that some of the information which we receive
through our senses is subjective and should not be trusted (secondary qualities), whilst other information
could be considered objective and constituted reliable knowledge (primary qualities).
From Locke's point of view, the thing that possessed these different qualities - the substance - could never
really be known in itself. If, for example, we consider once again the example of the table, we can be aware
of such things as its colour or texture (secondary qualities) or its shape and size (primary qualities). But we
cannot know the thing itself because everything we experience about the table will come under one of these
two categories.
The Irish philosopher George Berkeley (1685-1783), pointed out that the if all we ever see are secondary or
primary qualities, how do we know that substance really exists? In other words, there may be no such thing
as matter. This view is called Idealism.
Berkeley:
1) All we know is what we find in experience
2) We can never know or even make sense of a material world that allegedly
lies outside our own, private experiences
Conclusion: from Locke's empiricism to
the
denial of the world of independently
existing matter.
Berkeley's Criticism of Locke
Berkeley considered Locke and other philosophers to have opened the door to atheism and scepticism by
casting doubt on the senses. In an attempt to defend faith in God and knowledge from such attacks,
Berkeley attempted to show that, rather than sensations of objects arising from powers in the object itself
(as Locke thought), the experiences were in the perceiver (us).
What this means is that the object does not need to possess any powers with which it produces effects on
our senses, because the object does not exist apart from our perception of it. This allows Berkeley to deny
the sceptical argument that we do not see objects as they really are.
Berkeley's View of Reality:
My good man George Berkeley said “Esse est percipi,”
which means “To be is to be perceived.”
Arguments for Idealism:
The main arguments for Idealism are based on the idea that our perceptions of objects are in us. In other
words, when we say that an object is red, its redness is part of our perception of it, not in the object or - as
Locke argues - an effect of some power of redness in the object.
So what arguments does Berkeley use? First he attacks the idea that secondary qualities can exist in the
object:
I see a red chicken. But why?
Sensation. When you put your hand in cold water, the temperature feels different depending on the
temperature of our hand. If your hand is hot, the water will feel colder; if your hand is cold, the water will feel
warmer. The water cannot be hot and cold at the same time. Therefore the perception of temperature must
be in the perceiver.
Taste. If a taste is pleasurable, such as the sweetness of sugar, how can we say that pleasure exists in the
object itself (the sugar)? Therefore, since we cannot separate the taste of sweetness from our pleasure,
both must exist in the perceiver and not in the object (the same obviously goes for displeasure).
Next he tries to show that some perceptions are relative, attacking both primary and secondary
qualities:
Colour. If two people see the same object from different perspectives, one might think it was a
different colour to the other. Both colours cannot exist in the object at the same time, so the colour
must exist in the perceiver and not in the object.
Speed. If I am standing still and I see a train passing, the people on that train are moving at a
certain speed, but to each other they appear to be sitting still. If speed exists in the object, how
can the people on the train be both moving and at rest? The answer must be that the quality
exists in the perceiver.
Here Berkeley trues to show that there is no difference between real and apparent qualities:
The Master Argument. Berkeley's main argument is meant to show that it is impossible for
something to exist without being perceived (or, as he says, esse est percipi, Latin for "To be is to
be perceived"). This means that if we cannot imagine what the perception of something must be
like, we cannot really say that it exists. Berkeley uses this idea to attack the notion of substance or
matter, for if all the qualities that we ascribe to it are either primary or secondary qualities, can we
actually say that the substance itself exists?
According to Berkeley, only a mind can produce ideas (ie. Without the mind there can be no
experiences). If our minds did not produce the ideas or experiences we encounter, then God's
mind must have created them within us. God directly gives us the world of our experience
without the intermediate step of external physical matter.
Furthermore, God continuously maintains the world in existence, for even if
we are not experiencing a particular object, it still exists within God's mind.
*** Berkekey is challenging the traditional notion of what it means for
something to “exist.”
We can still enjoy the coolness of water and the warmth of fire. The only difference is that
we will realize that these experiences are in the form of mental events provided us by God.
Thought Experiment:
Does Berkeley's argument for the Mental Dependency of Ideas seem possible to you? If not,
why not?
Let's explore Berkeley's line of reasoning further. Pick up a pencil or pen.
What are you experiencing? You are probably having visual sensations of a
particular color, visual and tactile sensations of an extended length with
round or hexagonal sides, and tactile sensations of hardness.
Press the point of the pencil or pen into your palm and now you will have the
experience of pain associated with the pencil. But where is your pain?
Obviously, it is not located out in the external world. Pain is an idea (in Berkeley's sense of
the word) or an item within your experience. Yet this mind-dependant idea is part of your
experience of the pencil. And Berkeley would say that all the other properties of the pencil
have the same status. The sensations of color, shape, and extension in your experience are
just that—items within your experience. In describing the properties of the pencil, you did
not refer to anything external to your experience.
The Argument for the Mental Dependency of Ideas
1) Sensory objects (houses, mountains, rivers, and so on) are things
present to us in sense experience.
2) What is presented to us in sense experience consists only of our
ideas (or sensations).
3) Ideas exist solely in our mind.
4) Therefore, sensible objects exist only in our minds.
Conclusion: there is no external
physical world that exists apart from us
And now for our last Empiricist, a most erudite and intellectual
dude......although you may disagree with him
David Hume
Hume was an empiricist, for he believed that all information about the world comes
through experience. He is radical in his beliefs.
The contents of consciousness are what he calls perceptions.
A) Perceptions include our original experiences, which he labels impressions.
There are two kinds of impressions:
1) Sense Data Impressions (such as visual data, sounds, odors, tastes, and
touching
2) Internal Impressions (“internal” impressions are made from the contents of our
psychological experiences)
Hume defines these impressions as “all our more lively perceptions, when we hear, or see,
or feel, or love, or hate, or desire, or will.”
B) Perceptions also include what he calls ideas, or the contents of our memories and
imagination.
Obviously our impressions are more
vivid and trustworthy that the copies of
them we find in our ideas. Why?
Because for an idea to have any
legitimacy, it must be traced back to our
original impressions or combinations of
impressions
-I am an empiricist.
-I am a capricorn.
-I like Woody Allen films.
-I like long walks on the beach
-Every Thursday I order in
Chinese food.
-I'm on MySpace. Look for me
at [email protected]
Hume believed there's a huge gap between reason and the world. He
agrees with the rationalists that the logical relations between our ideas are
absolutely certain and necessary For example, there must be 180 degrees
in the concept of a triangle. BUT this conclusion only establishes a certain
relationship between a set of ideas.
IT DOES NOT DEMONSTRATE THAT THIS GEOMETRICAL RULE
IS TRUE IN THE PHYSICAL WORLD.
180º
According to Hume, we can only know this truth from observation.
The fact that this concept has always been the case when we've
used it to construct buildings does not guarantee that it will work that
way tomorrow.
Relations of Ideas (ie. Mental ideas) = always true
Matters of Fact (ie. “real life”) = not necessarily true
We can, according to Hume, deny ANY matter of fact. (ie. The sun will always rise in the
morning”)
The fact that we feel confident about certain facts about the world is
merely the result of our expectations, which are based on past
experience.
Maybe the sun won't rise
From here, Hume drives empiricism to
a radical extreme...
- We don't know with certainty that the future will be like the past. A limited number of examples
cannot prove a necessary truth (ie. 100 times doesn't mean the 101st time will be the same way)
Also, Hume sees miracles as being unlikely for this exact reason - that they have not been
observed often enough. Can this view be criticized?
....From here, Hume drives empiricism to a radical extreme
He thinks Locke and Berkeley have been inconsistent in working out the implications of their ideas.
Hume's basic argument:
If all we know are the contents of
our experience, how can we know
anything about what lies outside our
experience?
(Think about what this means if it's true)
- For Hume, all we can know are the personal contents of our
individual minds. All we can truly know is what we have experienced. It
is impossible to distinguish between the way things appear to us and
the way they really are. We cannot have knowledge concerning any
mind-independent reality.
If accepted, Hume's viewpoint makes it pointless to try to prove the existence of God (for example) as a
matter of fact. If God is not literally made up of physical matter, and does not have an observable effect on
the world, making a statement about God is not a matter of fact. Therefore, a statement about God must be
a relation of ideas. In this case if we prove the statement "God exists," it doesn't really tell us anything about
the real world; it is just playing with words. Do you agree with Hume's viewpoint? Why or why not?
Another point made by Hume: How do you know that if you touch a flame right now,
you will experience pain? How do you know that if you taste sugar, it will be sweet?
You are probably reasoning in this way:
(1) In the past, I have found that fire causes pain and sugar is sweet
Therefore
(2) When I encounter similar examples of fire or sugar, their effects will be similar to the
past cases.
Statement (1) is certainly true, but does it provide irrefutable evidence for statement (2)?
To get from statement (1) to statement (2) you need the following intermediate step:
(1a) The future will always be like the past.
But how do you know statement (1a) is true? Is it possible to prove the truth of such a
statement?
This is why hume is seen as a so science-friendly. He believed
firmly in inductive logic and reasoning. We arrive closer and
closer to certainty by observing the repetitive patterns in nature.
We do this through experience, not apprehending immaterial
rational truths (ie. rationalism).