Transcript Philosophy of Science

Conceptual Issues &
Psychology
Dr Roy Allen
School of Psychology
room: G09
email: [email protected]
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Readings associated with this lecture:
Cooper, R.M., (1982). The passing of
psychology. Canadian Psychology, 23, 264-267
McComas, W. (1996). Ten myths of science:
re-examining what we think we know.
School Science & Mathematics, 96, 10-16.
Popper, K. (1957). Science: conjectures and
refutations. In C.A. Mace (Ed.). British
Philosophy in Mid-Century: A Cambridge
Symposium. London: George Allen & Unwin
Ltd.
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About Exam Questions
Questions may come from one, some or none
of the Readings associated with this lecture.
Questions will be multi-choice, e.g.:
“Sir Karl Popper’s ideas regarding
falsifiability, were a rejection of:
a)
Logical Positivism;
b)
Epistemology;
c)
Formal Logic, or;
d)
Post-Modernism?
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Introduction
from 2nd to 3rd-year involves a change of
emphasis from books to peer-reviewed
journal articles;
tend to be out-dated; present information as
factual; gloss over detail;
tend to be more up-to-date; very dense;
focus on minutiae.
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Epistemology
Theory of Knowledge:
3.
“What is knowledge?“;
“How is knowledge acquired?“;
“What do people know?“;
4.
“How do we know what we know?”
1.
2.
How knowledge is acquired:
1.
2.
a priori/analytic – not requiring experience to
validate, e.g., "My father's brother is my uncle."
A posteriori/syntactic/empirical – requiring
experience to validate, e.g., “My father’s brother has a
black moustache
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Logical Empiricism & Science
1910s-30s Vienna Circle, coffeehouse group,
made a concerted effort to clarify the language
of science by arguing that:

the content of scientific theories could be reduced to
truths of logic and mathematics (analytic) coupled
with propositions referring to sense experience
(empirical).
They held that metaphysical speculation was
nonsensical, propositions of logic and
mathematics tautological, and moral or value
statements merely emotive.
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Verifiability 1
Deduction – the use of universal rules
or laws to explain an individual
observation, e.g.,
All diamonds are hard
Therefore this diamond is hard
Induction – the accumulation of individual
observations sufficient to produce a
general rule/law, e.g.,




Crow number 1 is black
Crow number 2 is black
Crow number 3 is black, etc, etc,
Therefore all crows are black
This is very much the “test/retest” approach of the “Scientific Method”
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Verifiability 2

Unfortunately, “universal” laws aren’t
always robust – so we have good reason to
assume that current scientific laws may also
be wrong too

Many of our laws are of the “all other
things being equal” sort- unsatisfying
because in a logical sense you can never be
sure of all other things being equal
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Verifiability 3

and individual observations never
seem to guarantee universality –
compare previous example with:
 Swan number 1 is white
 Swan number 2 is white
 Swan number 3 is white, etc, etc,
 Therefore all swans are white!

Doh!!
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Falsifiability 1
Sir Karl Raimund Popper (1902 – 1994):




Professor & Philosopher of Science @ London School of
Economics;
saw how unsatisfactory the observationist/inductivist
account of the scientific method was (i.e., Logical
Empiricism);
believed biggest problem in the philosophy of science was
“demarcation”, i.e., how to distinguish between science
and non-science;
was profoundly impressed by the differences between the
allegedly ‘scientific’ psycho-analytic theories of Freud and
Adler and the revolution effected by Einstein's theory of
relativity in physics in the first two decades of the last
century.
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Falsifiability 2
Popper realised that:

while Einstein's theory was highly ‘risky’, in the sense that it
was possible to deduce consequences from it which were, in
light of the then dominant Newtonian physics, highly
improbable and which would, if they turned out to be false,
falsify the whole theory (e.g., that light is deflected towards
solid bodies - confirmed by Eddington's experiments in
1919);

nothing could, even in principle, falsify psychoanalytic
theories…”;

He concluded that since proof was logically impossible,
scientists should, instead, aim to falsify theories and laws.
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Psychology 1

Sadly, in social/biological sciences like psychology we
don't have anything quite like the natural laws of
chemistry or physics, so we are forced to depend on
statistical explanations…

and these are inductive, not deductive in the way we
wish natural laws to be….

In the statistical inference approach, you have to
make assumptions about what you believe is the
relevant description (not really a cause) that
determines an outcome, e.g.:
• there is a 0.80 probability that a person voted New Labour
if their parents voted New Labour . . .
• but if they were a self-made millionaire it might be
a 0.55 probability . . .
• if they were a woman it might be a 0.62 probability . . .
• and, if she likes Gordon Brown it might be a 0.70
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etc etc etc.
Psychology 2
Is Ithe
statistical
inference
approach
a “stopbecause
gap” while
wait
for proper
have
always found
psychology
depressing
I camewe
into
it from
physics
and engineering
thinking that,
it experimentally
studied
thereal
human mind it
behavioural
and scientific
lawssince
to be
developed which
have
was a science. proof”-like properties?
“mathematical
 I soon realized that it was not a science but a catalogue, and a methodology for
adding
to the
I don't doubt
that itSociety's
is a useful
catalogue:
it's certainly
Pylyshyn,
Z.catalogue.
(1986). Cognitive
Science
Eighth
Annual
important
to know
such things
as how to help
people
Conference,
Amherst,
Massachusetts,
August
16.who are depressed or to
understand how people's memory or opinions can be changed in emotional
contexts or by clever questioning (say in eyewitness testimony).
 But many of us had hoped that there was a theoretical science like physics or
chemistry there somewhere and we were disappointed. I now believe that the
problem is simply that there is no unitary subject matter for psychology -- it is not
a natural scientific domain.
 But I find renewed hope now that within psychology lies one or more natural
scientific domains, and that cognition, suitably circumscribed to include those
aspects that are explainable in terms of symbol processing operations (together
with the non-symbolic mechanisms required to support symbol processing) may
be one of those natural scientific domains.
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Ten myths of science (McComas 1996)
1. hypotheses become theories become laws;
2. hypotheses are educated guesses;
3. there is a commonly-applied scientific method;
4. evidence leads to sure knowledge (i.e., the problem with induction);
5. science and its methods provide absolute proof (i.e., all swans are
white . . . Popper);
6. science is not a creative endeavour;
7. science can answer all questions;
8. scientists are objective;
9. experiments are the sole route to scientific knowledge;
10. scientific conclusions are continually reviewed.
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Learning Outcomes:







Know what epistemology is, and how knowledge is acquired;
Have a general idea about what Logical Empiricism is;
Know what deduction and induction are, and the problems of
verifiability;
Understand Popper’s criticism of Logical Empiricism and his notion
of falsifiability;
Have a clear understanding about some of the myths (at least 10)
associated with science;
Have some feeling for the particular problems associated with
knowledge acquisition in psychology;
Understand, and respond to, some of the criticisms directed towards
psychology as regards its “passing”.
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