PHILOSOPHY 214:
TERM 1
Philosophy of Science
Notes by Layla
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THE STANDARD IMAGE OF SCIENCE
The image/conception of the nature of science and its method at the beginning of the century is
largely influenced by the view of J. S. Mills.
This standard image has several features/assumptions, such as:
- science is completely objective and rational
- scientific knowledge is acquired precisely the same way everywhere and always: in this way it
is both formalistic (method that anyone can follow anywhere in space and time to get the
result of science) and a-historical (not dependent on history— results will be the same in
anywhere and any place) image
- completely value free (subjectivity of scientist/values of historical community of which science
forms a part, play no role in acquisition and status of scientific knowledge).
- relies on generalisations
- such generalisations are theories that formulate so called laws of nature
In regards to the last assumption, we know that sensory experiences are always distinctive/
individual/particular. So how do we move from the latter to the generally valid knowledge of laws
of nature?
Through inductive generalisation as reasoning strategy— also known as induction.
INDUCTION/EMPIRICISM VIEW
Logic can be either deductive or inductive. While a deductive argument is one in which reasoning is
used to reach a logically certain conclusion from one or more statements, and inductive argument
is one in which the premises are viewed as supporting the truth of the conclusion, increasing the
probability that it is true.
Induction is an empirical method.
The process of inductions suggests that by finding individual truths about nature/science we can
make generalisations. Induction is such that premises make the conclusion more probable/
probably true. ex: general laws like ‘copper expands when heated’ can only be found by heating
different bits of copper until they melt, therefore increasing the probability that all copper
expands when heated.
Of course, this never guarantees that all copper expands when heated but the likelihood that
copper will melt is higher every time a new piece of copper expands when heated.
Induction proceeds as follows:
1. Sensory observations are made first
2. Based on these sensory observations we can make singular judgements ( such as “this piece
of iron expands when heated” and “that bit of iron expands when heated”)
3. A hypothesis is made using these singular judgements (such as “all iron expands when
heated”)
4. Broadening of experiences to test hypothesis (i.e. heating more and more pieces of iron,
in various shapes, sizes, and settings)
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5. General theory which formulates “laws of nature” is produced (ex: All iron expand when
heated.)
However, there are some notable objections to the view of induction as the basis for all science.
PROBLEMS WITH INDUCTIVE IMAGE OF SCIENCE
1. Hume’s problem:
Is it logical, in the light of limited experiences, to make a claim with universal validity? How can it
be rational to apply past cases to future cases. There is no way to rationally trust that induction will
even give us probability.
Trusting induction is a circular argument.
J.S. Mill’s argues that, Yes, it is logical, because:
- Induction assumes that the universe is uniform in behaviour. It suggests that ‘what we see here
can be applied everywhere.’ Mills argues that by doing this it does not assume everything is
uniform, just that there is some uniformity in the world and a probability that things will be
uniform.
- That all swans are not white (as believed for centuries), is not refutation of induction, but merely
indication of too limited field of experience upon which theory was based
- Why do we take “all crows are not black” more seriously than “there are people whose heads are
lower than their shoulders”? We do this because we know that the color of crows can vary but
people’s physiology cannot through prior induction.
2. Hembel’s paradox:
(not mandatory for exam)
Hembel brought about the claim all ravens are black means the same as ‘all non-black things are
not ravens.’Hence the more non-black things we see that aren’t ravens the more support our
hypothesis gains.
The reason that this is illogical is because we could say for example that a pink umbrella supports
the hypothesis ‘all non-black things are not ravens and therefore that all ravens are black’ because
it is a non black thing that is not a raven.
3. At what point can we begin to generalise?
at which point do we go form ‘this copper expands and that copper expands, so all copper
expands’? generalisation becomes more and more probable.
POPPER’S FALSIFIABILITY VIEW
Karl Popper disagreed with the view that induction is the standard image of science. He claimed
that while science does starts with some impartial observations, this observation is only useful if
guided by an idea. As a result, a large majority of Popper’s early work in the philosophy of science is
directed toward what he calls the problem of demarcation, or the problem of distinguishing
scientific (or empirical) theories from non-scientific theories.
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Some claims that Popper made regarding the standard image of science are:
1. According to Popper, it would be more useful then, to say science does not begin with
observations, but with problems that need to be solved.
Ideas come first, and then via critical rationalism, it is criticised it until it becomes better.
When Popper says that science begins with problems, he means in the sense of frustrated
expectations. This is when we are expecting something to happen, or expecting an
experiment to have a specific outcome, and then it doesn’t— our expectations are
frustrated/not met.
To have frustrated expectations you need to have expectations (theories) first. Popper’s
philosophy is based on the idealisation of trial and error— when theories are tested and
refuted is when science progresses to new levels and teaches us new things. Popper says
there are two things necessary for trial and error:
a. options/new ideas need to be generated and
b. some condition needs to exist/occur in which we can say without a doubt that the idea
was wrong.
2. Popper believes that the subjectivity of science is evident from necessity to formulate
"bold conjectures" as forerunners of hypotheses and theories, and that is what’s
important, more so than the source of these conjectures/presumptions.
When analysing a theory, there are two things we look at:
a. context of discovery: where does a theory come from?
b. context of validation: how do we test a theory?
Popper believes there is no science in context of discovery, only in the context of validation,
i.e. how we test a theory. While induction suggest that these are both objective processes,
Popper believes the first is subject because a theory is not an observation, it is a possible
solution to a problem. He therefore, believed that the first process is subjective rather than
objective. The second, however, remains an objective process in both theories.
3. Another claim that Popper made was that scientific character and rationality are
determined by testability (falsifiability). Popper believes even if we could arrive at
theories by induction, if they are falsifiable, then they are scientific. Falsifiability means that if
the theory is false, then we should be able to prove that it is false. Good theories are falsifiable
— that doesn’t mean that they are false but rather that if they are, then we can find out they are.
Take Newton’s force law, for example, or Einstein’s theory of relativity, etc. Even a law as
simple as ‘all metal expands when heated’— this theory is a good scientific one according to
Popper, because it is falsifiable. It can be tested over and over and never be fully verified but
one observation (an instance where metal does not expand when heated) can disprove the
entire theory.
This is why Popper believes theories such as Freud’s psychoanalysis are unsatisfactory
because they are irrefutable and therefore unfalsifiable. It can never be proven wrong, but
that doesn’t mean it is correct.
4. Science strives towards high empirical content and low probability.
According to Popper, this is because the more empirical content a claim has, the less
probable it is, the less likely it is to be falsified. High empirical content means that if a
theory is proven true, it can be regarded as science because it is more falsifiable than a
theory that has low empirical content & a high probability.
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