Chapter 4 Natural Sciences
Lesson 1 Scientific Method,
Hypothesis, Observation, and
Knowledge
Does science really help us know as much as it seems?
Science
• Science is seen as a sign of progress and
success
• It is a form of control
• It has made us see and understand the
world differently than people of the past
• The scientific revolution is as much a
revolution in humankind’s way of thinking
as it is in our way of living
We are born into a world where…
• scientific knowledge—empirical knowledge—is
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supreme
anything observable is fact and anything not
observable is fantasy
We think scientifically
When we behave sanely and acceptably, we
behave rationally and logically
We respect scientists and honour comes through
scientific means
However, does science really give
us knowledge?
• Some will say immediately that it does
• Some will argue that it only gives us a
strong belief
• Some will argue that science only allows
us to control our surroundings, but as far
as important knowledge is concerned, it
falls short
• What do you think?
The aims of this chapter are to…
• Examine how we know what we know in
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science
Understand what is actually being said when
a scientist says she “knows” something
Examine the problems with knowledge claims
in science as well as the process involved in
developing scientific claims that seem sound
Knowledge through Theory and
Observation
• Science is based on observation
• However human beings observe similar stimuli differently
• Copernicus observed that the horizon was actually falling away from
the sun, while Ptolemy saw the sun moving up above a stable
unmoving horizon
Is the sun moving up or is the horizon falling down
away from the sun?
The Scientific Method or “the best
way” to get true statements about
the natural world
• 1. Observe some phenomenon in the universe
• 2. Invent a tentative description or answer, called a
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hypothesis, that is consistent with what has been
observed
3. Use the hypothesis to make predictions
4. Test those predictions by experiments or further
observations and alter the hypothesis in the light of the
results ’
5. Repeat steps 2, 3 and 4 until there are no
discrepancies between theory and experiment and/or
observation
The scientific method is successful,
however there are problems.
• First step in the scientific method is direct observation
• Observation seems simple enough, but observation is
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not unproblematic
Consider again the example of Copernicus and Ptolemy.
They both correctly recorded what they observed, but
there observances were contrary to one another
This is indeed a paradox. If all science is based on
observation, and what one observes can be different
depending on the theories or expectations one has, then
how sound is the knowledge one actually gets?
The Influence of Theory on
Experience
• Theories are present in every
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part of our experience as they
were for Copernicus and Ptolemy
Whether we see a duck or a
rabbit depends on what we
expect to see
Theoretical preconceptions are
with us all the time and they
have some sort of effect on
observations made during
scientific investigations
Duck-Rabbit Illusion
What this means for knowledge in
science is that
• If all experience is influenced by theories and
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preconceived notions, then it is impossible to
make observations which are not in some way
contaminated by these theories and
preconceived notions
Subsequently, if a scientist is to test theories and
hypotheses by making observations and the
observations are tainted by the theories, how
objective can the observations and the
conclusions actually be?
Can this possibly lead to objective knowledge?
How theories influence what is
noticed
• It can be argued that observation is a process that is
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guided by our theories and hypotheses
These theories actually direct our observations by
making us aware of which stimuli are significant and
which are insignificant
Science works by observing specifics; by finding data
which will either confirm or disconfirm our specific
theories and hypotheses
Scientists do not “drag the bottom” with a net hoping to
find something valuable
If a scientist is going to observe something the first step
is deciding what to observe
Important points
• Without any theory or hypothesis it would be
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impossible to observe anything at all significant
Without theories guiding the observation
process, random observations would be useless
at confirming or disconfirming hypotheses
Because of this, it is possible the scientist only
notices what he expects to see
It is also possible that he can only discover
things when they correspond to or conflict with
what he expected to discover in the first place
Real life examples illustrating this
phenomenon
• Professor Wilhelm
Conrad Roentgen and
the surprising
discovery of X-rays.
• Alexander Fleming
and his lucky
discovery of penicillin
Early X-ray photos.
The left image is of
Mrs. Roentgen’s hand
Is observation really the key to
scientific knowledge?
• How many amazing life-improving
discoveries have we missed out on
because the scientists have been limited
to confirming or disconfirming their
theories, while other significant facts are
ignored or not observed?
• Is it possible that the scientific method
itself actually limits scientific discovery?
Critique of these two claims
• We can count on our observations most of the
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time
Observation is the only tool a scientist has for
coming in contact with the universe. What other
choice is there?
Examining the success rate of scientists from a
pragmatic perspective it becomes clear that their
observations are correct a great deal of the time
There is only a limited amount of flexibility in
our observations
Critique of these two claims
(contd.)
• When a scientist directs his attention
towards one thing it does not necessarily
mean that he will exclude himself from
discovering something else
• It is a necessity to direct our attention
towards something specific because at any
given moment we are literally inundated
with stimuli
Lesson 2 Induction
Induction and its Importance to
Science
• Induction is making predictions about
future events based on past experiences
• This is exactly what science does.
• Science would not work at all if what was
expected to happen never did happen
The problem with inductive
reasoning
• The problem with inductive reasoning is that there really
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is no way to tell the future and just because something
has happened many times in the past does not mean it
MUST happen again in the future
There is no physical law which forces events to take
place on account that they have taken place before
The paradox of science is that science is totally based on
making predictions about future events based on past
experience, but there are no grounds for assuming that
because something has happened in the past that it
must happen again in the future
Can anyone claim to really know anything scientifically?
David Hume: Inductive reasoning is
irrational
• Science falls into the category of
expectational knowledge
• Hume asserted is that it is
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irrational for us to believe that
all of these things will happen
again in the future (unobserved
instances) just because they
have happened in the past.
Hume had two main problems
with induction
David Hume 1711-1776
Hume’s first problem with
induction: The Logical problem
• The Logical Problem. Hume asks
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the question: Are we logically
justified in reasoning from instances
we have experienced repeatedly
(i.e. success with a vaccine, (to give
a modern example)) to instances of
which we have no experience (i.e.
that the vaccine will work next
time)?
His answer to this is a definite “No!”
There is no logical justification
whatsoever.
David Hume 1711-1776
Hume’s second problem with
induction: The Psychological
Problem
• The Psychological Problem. The
question here is: Given the fact
that induction is so illogical, why
do all people, even reasonable
people, like scientists, believe
that unobservable events (future
outcomes or other instances
which they have not
experienced directly) will
conform to past events of which
they have experienced?
David Hume 1711-1776
Hume’s answer to:
The Psychological Problem
• We think this way because we
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have been conditioned to think
this way through association.
We are conditioned through
repetition
It may not be rational, but
inductive reasoning is necessary
for survival
David Hume 1711-1776
Hume’s assertion
• What Hume argues is that we have no
rational reason to believe that induction
actually gives us knowledge. Since science
is based on induction, Hume argues that
there is no rational reason to believe that
science actually gives us “real” knowledge.
We simply believe it because we are
habitually used to living our lives by way
of inductive reasoning.
Popper and falsification
• Agrees with Hume that
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induction is irrational
Asserts science is about
regularities.
Knowledge comes from finding
counter-instances.
A counter-instance is an
instance in which disproves the
regularity
Karl Popper 1902-1994
Knowledge through falsification
• Popper asserts “Logic
forces us to reject even the
most successful law the
moment we accept one
single counter instance”
• To find knowledge in science
Popper argues that we must
instead look for counter
instances, or, in other words,
instances which disprove the
law or regularity
Karl Popper 1902-1994
What this implies is…
• Nothing can actually be proven true
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and the strength of science lies in its
meticulous ability to falsify
assumptions
A scientist tries to find instances
where his hypothesis does not hold
true
The more he tries to falsify it, and the
more he and other people fail to
falsify it, the sounder and more
probable the claim becomes
Eventually when enough people have
failed to falsify the claim, the claim
becomes accepted as knowledge
Karl Popper 1902-1994
What this implies is…(contd.)
• Science hopes to find theories
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that are true.
While actual “truth” may not be
fully possible to determine, it is
possible to eliminate the false
theories, and the more the
theory in question holds up to
the process of falsification, the
more likely it is to be true.
At least any belief in the theory
will be a more firmly founded
belief.
Karl Popper 1902-1994
Lesson 3 Science and
Pseudoscience
Pseudoscience
• A pseudoscience is,
any body of knowledge,
methodology, or
practice that is
mistakenly thought of
as science
Recognising a Pseudoscience
Asserting claims or theories
unconnected to previous
experimental results
• If something is to be classified as
“scientific” it must have been tested
through experiment
• This is not done in pseudoscience
Asserting claims which cannot be
verified or falsified
• Pseudoscience makes
claims that can neither be
falsified nor verified
• Many claims made by
pseudoscience can not be
tested at all
Asserting claims which contradict
experimentally established results
• Simple and
straightforward. A
pseudoscience often
makes claims that
contradict facts which
are proven.
“Prove it!” Sceptic James Randi
offers $1,000,000 for conclusive proof
of paranormal ability such as ESP
Failing to provide an experimental
possibility of reproducible results
• The ability to replicate
results is key in
science. Pseudoscience
fails to provide
reproducible results.
Failing to submit results to peerreview before making public claims
• Responsible scientific claims are
scrutinized by knowledgeable peers before
the claims are made public. This does not
happen in pseudoscience.
Little or no evolution of the field
and its claims since its beginning
• A pseudoscience is
stagnate. The
“science” does not
develop. The
knowledge claims
stay the same as they
always have been
Pseudoscience is often motivated
by commercial goals
• Money Money Money!
• Money is almost
always involved in
pseudoscientific claims
Who profits from pseudoscience?
Is pseudoscience without value?
• Maybe. Just because pseudoscientific
claims have not been verified, it does not
mean that they are not true
• Many questions can not be answered by
science. Maybe pseudoscience is of value
in this sense
Things to keep in mind
• An extra helping of critical thinking is
imperative when considering
pseudoscientific claims
• If it seems too good to be true it probably
is
• If someone has something to gain by their
pseudoscientific claims, then they are
likely out for gain
Lesson 4 Faith in Science
“Science is the great antidote to the poison of enthusiasm and superstition.”
Adam Smith (1723-90) Scottish economist.
The Wealth of Nations, 1776.
The role of science
• As the world becomes all
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the more secular, science
is given an increasingly
important role in our
society
Science replaces traditions
which have been with
human civilisation for
many centuries such as
voodoo and the belief in
ghosts
If something is not
observable or measurable
it is not real
How science works
• Science has taught us to believe what is
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observable and to reject that which is not
observable
This belief is the cornerstone and the strength of
science since it helps the scientist avoid bias and
it gives pragmatic, useful information
Science rejects claims that can not be backed up
with empirical data
Faith?
• Many traditional areas make knowledge
claims based on faith
• What about science? Is there room for
faith in science?
• Can knowledge claims in science be based
on faith?
• It depends
No Faith in Science/Faith is always
in science
• The following parts of
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this lesson consists of
two contrasting
speeches/essays
which are designed to
be read aloud in class.
Discussion questions
follow
Images from the two
speeches/essays are
included here
No Faith in Science/Faith is always
in science
Would we get here by faith alone?
No Faith in Science/Faith is always
in science
This telescope in Hawaii just helps us
observe what is really there.
No Faith in Science/Faith is always
in science
Who has actually seen an atom anyway?
No Faith in Science/Faith is always
in science
This is how luminiferous aether was supposed to have worked.
Lesson 5 Does Science Give Us
Real Knowledge?
Is the “truth” out there?
The influence of science
• Science has affected every aspect of our lives
• Try for a moment to think of something you
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know or do, which is not, in some way, affected
by science or scientific thinking
But, do all of these changes, all of this science
and scientific thinking, actually give us any real
knowledge?
Some will say “Yes, obviously”
• Because it allows us to do so very much
more than we could if we did not know
the scientific things we do know
However…
• There is a chance though that we are mistaking being
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able to control our environment with knowing our
environment
Perhaps we are mistaking describing the world around
us with knowing the world around us
Perhaps science does not give us any real knowledge
about the things which are important to humanity
What happens when we die? Why are we here? What
does beauty and love mean? Why do the stars and
planets exist?
Is science dehumanising?
Is it simply a good tool?
Positivist: Science gives us
knowledge
• Knowledge is knowing how to
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navigate through our
environment. Science is the tool
that helps us do this task
Science is pragmatic in this
sense. Things in the world
either work or they do not
By seeing if it works or not,
observer will know if the
technique was a good one or a
bad one
Measurement. Precision: Predictability.
These are the keys to knowledge.
Positivist: Science gives us
knowledge (contd.)
• Nature is out there whether we are here to observe it or
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not
Scientists are predators looking for facts about how the
world works away from their own subjective
interpretations
Scientists are observing what is out there. They do not
create the things which they observe, like a poet does a
poem
The reason science creates real knowledge is because it
makes clear relationships about the real world
There is no room in this process for subjectivity
Positivist: Science gives us
knowledge (contd.)
• Science also produces real knowledge
since the knowledge works for everyone
• Ambiguity is fine for poems, but when
going to the doctor, or when getting
energy from the local nuclear power plant,
what is needed is not ten different
interpretations but one answer
• Science is about answers
Positivist: Science gives us
knowledge (contd.)
• Science produces knowledge because it is
objective
• It obtains this objectivity and rationality to a
great extent from its meticulous method of
confirmation
• If we can predict an outcome, then confirm our
prediction with indisputable empirical data, we
have confirmed our knowledge about the world
Positivist: Science gives us
knowledge (contd.)
• Repeatability is the key to, and
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the strength of, science
When an experiment has been
successfully repeated enough
times a scientist knows that his
knowledge is a reflection of how
things really are, and not how
someone just believes or wants
them to be
Another way to show that
science actually produces
knowledge is that scientists can
predict the outcome of events.
Predictability is the proof of
knowledge
There is no proof in this pudding.
That’s what predictability is for.
Positivist: Science gives us
knowledge (contd.)
• Science has a self-correcting mechanism built into its
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structure
no theory can ever be completely proven true because
there is always a possibility that in some circumstance
the processes that have always worked will not work or
will work differently
knowledge in science is only knowledge until some
discovered fact proves that which we thought was true
to be incorrect
Because of this, the knowledge in science increases
constantly
Romantic: Real knowledge? No
• It is rather ironic that
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science has spent so much
time refuting the claims of
religion while at the same
time it tries to answer many
of the very same questions
that religion answers
Has science become a
religion?
Will science help us know this
or merely describe it?
Romantic: Real knowledge? No
(contd.)
• Science is not a useful tool
• Many of us benefit from using the tool
• However what is important to remember is that
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science is merely a tool and nothing more
It teaches us how to manipulate our
environment
But there is no real understanding behind the
process
Romantic: Real knowledge? No
(contd.)
• Science prides itself on measurement but, how
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successful can science be at measuring love or
hope?
What does it know about living life as a human
being and finding comfort in the love of another
person?
Is not love real? Yet, it cannot be measured
Being human is about love, inspiration, fear,
hope, and desire. Not empirical numbers filled
out on some chart
Romantic: Real knowledge? No
(contd.)
• Living is about being subjective
• However science has nothing but
contempt for everything subjective
because the subjective is inaccessible to
science
• In this sense, the human experience is
inaccessible for science
• Science is dehumanising
Romantic: Real knowledge? No
(contd.)
• Science is a way to describe
things. It is a wonderful
descriptive tool
• Science has mistaken
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description for truly
understanding
Science is about control, it is
not about comprehension
Perhaps quarks do look like this.
Then what?
Romantic: Real knowledge? No
(contd.)
• Truly important questions about our existence
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are not only unanswered by science, but can not
be answered by science
Everything must be observable in science. But
everything is not observable when it comes to
human beings
Are not our feelings and thoughts more real
than quarks or strange things like dark energy
which we will never see?
Romantic: Real knowledge? No
(contd.)
• Science is a useful tool
• But it is important that we keep science in
the right perspective and not look to it for
the answers to the really important
questions
• If we keep this in mind then we can make
use of the tool of science and benefit from
it