EMPIRICISM MOTIVATIONS

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EMPIRICISM MOTIVATIONS
Rationalists are spiders they spin complex
metaphysical systems out of their entrails.
Empiricists are bees they gather pollen
(data) and works it into honey (knowledge).
Francis Bacon (1561-1626)
The book of nature is written in the language of
mathematics.
Nature is to be probed by observation and
experimentation science.
Pioneering use of telescope led to discoveries
that undermined Aristotles view of the heavens.
Galileo Galilei (1564-1642)
There are no innate ideas.
Knowledge is the agreement of ideas that
originate in experience.
John Locke (1632-1704)
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Empiricism
The fundamental source of knowledge is experience.
Only through experience can gain scientific
knowledge
Copernicus (1473-1543)
Ptolemy had formalised how the idea that the
Earth was the centre of the universe with all the
planets and the Sun orbiting it on nested
epicycles. Not true. The Earth orbits the sun.
Aristotle had taught that heavier bodies fall
faster than lighter ones (in the same medium).
Not true. They fall at the same speed.
Aristotle had taught that a moving body stays in
motion only because it continues to be propelled.
Not true. Bodies have inertia basic resistance
to change of velocity.
Galileo (1564-1642)
Everything orbits the Earth, it used to be
claimed. Not true. Jupiter has its own moons.
It was claimed that the moon is perfectly smooth.
Not true. The moon is pitted with craters.
The sun rotates around an axis. I discovered this
by observing the motions of sunspots.
Harvey (1578-1657)
Galen taught that the venous and arterial systems
are separate. I discovered the heart is a pump
that is fed by the arteries and feeds the veins.
Brahe (1546-1601)
In 1572 a bright star appeared (it was what we
now call a supernova). I showed it was indeed a
star by showing that it did not move relative to
the other stars. This contradicted the prevailing
view that the heavens were unchanging.
Newton (1642-1727)
I formulated the three laws of motion and the law
of gravitational attraction. I made respectable
the idea of action at a distance. I also showed
that celestial and terrestrial motion are the
same (rectilinear), against Aristotle.
The modern approach was to think of matter as
made of up of corpuscles and for elements to be
made out of different arrangements of
corpuscles atoms or perhaps mixtures of
different types of corpuscles.
The Aristotelian system of elements contains
earth, air, fire, wind and quintessence.
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Empiricism
The fundamental source of knowledge is experience.
Locke Knowledge is of necessary truths, of the
unchanging and deep nature of reality. We learn
these truths by discovering connections between
ideas we get ultimately from experience.
Hume Substantial knowledge is of contingent
truths gained through experience. Knowledge of
necessary truths is merely knowledge of trivial
definitions (analytic truths).
Hume true, but we have to start with our minds
as they create the world for us.
Locke knowledge of the reality behind
appearances is what matters to philosophy.
Our senses, properly used, can yield infallible
and objective knowledge.
Reason, properly used, is infallible and
objective. It is limited but we can recognise its
limitations.
Necessary truths are knowable a priori reason
alone provides justification
Contingent truths are knowable a posteriori
experience alone provides justification.
We have no innate ideas (innate knowledge). Each
of us is born as a tabula rasa a blank slate.
Experience gives us ideas that the mind can use
to generate more complex ideas.
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Empiricism Fundamental Motivations
Reason cannot yield scientific knowledge of the
world.
Look at how wrong the scientists of the past
have been.
Scientific knowledge requires the testing of
hypotheses by experimentation.
Look how successful science has been.
There are no innate ideas.
We do not share the same ideas
We can explain the origins of our ideas
empirically.
And we can show that supposed metaphysical truths
are nothing more than contingent falsehoods that
appear true because of our psychology.
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EMPIRICISM LOCKEAN MOTIVATIONS
How could you know necessary truths such a
nothing can be both black and white without
experience of these colours?
There are no innate ideas.
Whats the proof?
John Locke (1632-1704)
But even if there were things we all agreed on,
this wouldnt show they were innate. They could
arise from common types of experience.
E.g. we all learn the ideas of red and object and
sky because we all experience these things.
If there were innate ideas/principles, theyd be
universally assented to.
All ideas are either come from sensation or
reflection. The simple ideas of sensation are the
fundamental ideas.
Children, idiots and savages are unaware of
concepts such as God and cause.
There are no moral rules common to every society.
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LEIBNIZS REACTION TO LOCKE
The marble has veins running through it that
define a statue of Hercules.
A mind is not a tabula rasa. It is like a block
of marble.
Our ideas are innate but not actually present in
the mind.
Gottfried Leibniz (1646-1716)
Experience is therefore necessary for knowledge
but not sufficient.
In the same way, our ideas are potentially in our
minds but we need the right experiences to
activate them
By hitting the marble at its veins, the embedded
statue becomes exposed.
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EMPIRICISM LOCKE AND NECESSARY TRUTHS
We cant learn that all triangles have internal
angles that sum to 180o through experience we
cant check all of them.
We learn the ideas of triangle, angle, degree and
so forth from experience.
Once we have these ideas, we can consider their
relations to one another in our mind.
But how do we account for knowledge of necessary
truths?
We can observe that it follows from the idea of a
triangle and the idea of an angle and the idea of
180 that a triangle must have internal angles
that sum to 180o
and you cant say as all triangles have
property X so it is necessary property without
having experienced all triangles
You cant say all triangles have this property
so it is necessary without having the idea of
necessity
and you cant say well, my idea of a triangle
shows it to have property X on the basis of what
I have seen so far, because thats no proof it is
necessary for all we know, all the triangles
youve seen so far might have been green.
It presupposes we have the idea of necessity. How
do we learn this from experience?
So, we learn necessary truths by examining our
ideas and the relationships between them.
How does our mind succeed in representing just
the necessary features?
But this doesnt solve the problem.
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EMPIRICISM HUMEAN MOTIVATIONS
Humes Copy Principle All our simple ideas in
their first appearance are derived from simple
impressions, which are correspondent to them, and
which they exactly represent
Our mind makes ideas faint copies of impressions
that enable us to think off-line.
All knowledge begins with impressions the
deliverances of the senses.
David Hume (1711-1776)
Proof?
Impressions enter with the most force and
violence or are more vivacious than ideas
People lacking either a sensory modality (e.g.
taste) or impressions (e.g. tastes of wine)
cannot form ideas of these things.
Find me an idea that does not originate in
experience.
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EMPIRICISM HUMEAN MOTIVATIONS
What about necessary truths? And metaphysical
concepts of God and cause and self?
The books of metaphysics should be consigned to
the flames
There are no substantial (interesting,
metaphysical) a priori knowable truths.
Relation of ideas analytic and necessary
truth. All bachelors are unmarried The idea
of unmarried is analytically part of the idea of
a bachelor.
But what about important metaphysical truths such
as God exists? Every event has a cause?
Humes Fork Any truth is either a relation of
ideas or a matter of fact
Either they are mere truths of definition or they
are, if true, only contingently so.
Matter of fact synthetic and contingent
truth. Bernard is a bachelor The idea of
being a bachelor is no part of the idea of
Bernard. Its just a fact about Bernard that he
is a bachelor.
I can conceive of an uncaused event, so it is not
necessarily true not even by definition that
every event has a cause.
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HUME AND CAUSATION
Furthermore, theres no real relation of
causation out there in the world. Causation is a
psychological relation between impressions/ideas.
Rationalists say that the concept of cause is an
innate concept and that we live in a world where
nothing happens without a cause.
The concept of cause is learned from experience.
We get the idea of a necessary connexion from
seeing X and Y together many times.
Necessity is psychological not metaphysical.
Suppose that a brick is thrown at a window and it
breaks. We say that the thrown brick caused the
broken window.
Whats a necessary connexion? How can experience
discover this?
But does it follow logically from the description
of the first event the thrown brick that the
second event the broken window would follow?
So, causation boils down to the expectation that
Y will follow X.

• X causes Y
• X and Y are spatiotemporally contiguous.
• X comes before Y
• There is a necessary connexion between cause and
  effect.

So, what does it mean to say that one thing
causes another?
So reason cannot discover causal connections.
No!