A common sense view of science
RMMR
Research Methods, Management
and Reporting
“science
science is delivered from facts
facts”
Lecture 8: Introduction to the thing called science
Galileo and the Leaning Tower of Pisa
P f Wlodek
Prof.
Wl d k Kulesza
K l
[email protected]
http://homepage.te.hik.se/personal/tkuwl/
A common sense view of science
Scientific
f knowledge
g should in some
way be delivered from facts arrived
at by observation.
Pre-Galileo assumption:
knowledge is based on authority
How is science delivered from facts?
- Facts are directlyy given
g
to careful,
unprejudiced observers via senses
- Facts are prior to and independent of
theory
- Facts constitute a firm and reliable
foundation for scientific knowledge
Science is delivered from facts
A widely held common sense
view of science
Seeing is believing!
Do we see the same things?
How visual experiences are
determined by:
• experience
• knowledge
• expectation
Issues of the claim that
science is delivered from facts
Pre-assumption of the claim that
science is delivered from facts
•Nature
N
off fact
f
•How to have access to facts
•How laws and theories are delivered
from facts
Single, unique physical world exist
independently of observation
Meaning of “facts”
A statement that expresses
p
the facts.
The state of affairs referred to by such a
statement.
What are knowledge
g based on and
delivered from?
• The state of affairs?
• Factual statement?
Why should facts precede theory?
The search for relevant observable
facts in science is guided by
w g
knowledge
Meaning of “facts”
The appropriate
Th
i conceptuall framework
f
k andd
knowledge of how to appropriately apply it
are necessary to formulate and assent to
observation statement
Observable facts are objective but fallible
Objective since they can be publicly
tested
Fallible since they may be undermined
by new kinds of tests made possible
by advance in science and technology
Experiments
If there are facts that constitute the
basis for science, then those facts
come in the form of experimental
results rather than old observable facts
Delivering theories from the facts:
induction
Arguments proceed from a finite
number of specific facts to a general
conclusion are called inductive
arguments as distinct from logical,
g
deductive arguments.
Experiments
Experimental results can:
¾become outmoded because of
advance in technology,
¾can be rejected because of some
g,
advance in understanding,
¾can be ignored as irrelevant in the
light of some shift in theory
understanding
Requests of a good inductive
argument
• The number of observation
• Repeatability under a wide variety of
conditions
• No accepted observation statement
should conflict with the delivered law
Inductivist view of science
The concept of verification replaced with the
id off “gradually
idea
“ d ll increasing confirmation”.
f
”
Law and theories
induction
Facts required
thought observation
Logical Empiricism
deduction
Prediction and
explanations
Logical Empiricism
The logical empiricist’s use of a probabilistic
interpretation
p
does not avoid the pproblem off
induction.
Example: Just because the sun has risen every day for as long as anyone
can remember, does not mean that there is any rational reason to believe it
will rise tomorrow
The argument that induction has worked successfully in the
past is itself an inductive argument and cannot be used to
support the principle of induction (Chalmers).
Universal statements could never be verified, but they may be
“confirmed” by the accumulation of successful empirical tests.
Thus, science progresses through the accumulation of multiple
confirming
fi i instances
i t
obtained
bt i d under
d a wide
id variety
i t off
circumstances and conditions.
Popper and Falsificationism
Are the theories,
theories which never can be
wrong, scientific?
E.g. Freudians, Adler
Key Popper’s
K
P
’ idea:
id
Scientific theories are falsifiable!
Popper and Falsificationism
The truth content of our theories, even the best
off them,
h cannot be
b verified
ifi d by
b scientific
i ifi testing,
i
but can only be falsified.
Popper and Falsificationism
Observation always
y presupposes
p
pp
the existence
of some system of expectations.
Theories cannot be established as true or
probably in the light of observational
evidence.
evidence
Popper and Falsificationism
The scientific p
process begins
g when
observations clash with existing theories or
preconceptions.
To solve this scientific problem, a theory is
proposed and the logical conseq
consequences
ences of the
theory (hypotheses) are subjected to rigorous
empirical tests.
Popper and Falsificationism
Theories are constructed as speculative
p
and
tentative conjectures or guesses freely
created by the human intellect in an
attempt to overcome problems
encountered by previous theories to give an
adequate account of some aspects of the
world or universe.
Popper and Falsificationism
No scientific theory can claim to be true,
it can only be
b said:
d it is the b
best available!
b
Fundamental condition:
Any hypothesis or system of hypothesis must be
falsifiable if it is to be granted the status of a
falsifiable,
scientific law or theory
Popper and Falsificationism
An h
A
hypothesis
h i iis ffalsifiable
l ifi bl if there
h iis a
logically possible observation statement
that inconsistent with it, that is, which if
established as true, would falsify the
hypothesis
Popper and Falsificationism
It never rains on Wednesday!
Either it is raining or it is not raining
All points on a Euclidean circle are equidistant
from the center
Luck is possible in sporting speculation
L k is
Luck
i impossible
i
ibl in
i sporting
i speculation
l i
The aim of science
Theory can be falsified and rejected but it
cannot be established as true or probably true.
The aim of science is to falsify theories and
replace them by better, which demonstrate
greater ability to withstand tests