Okasha Philosophy of science
Contents
Ch1 - what is science..................................................................................................................1
Ch 2 - scientific reasoning..........................................................................................................1
Ch3 - explanation in science.......................................................................................................4
Ch4 - realism and anti-realism....................................................................................................7
Ch5 - Scientific change and scientific revolutions......................................................................9
Ch6 - Philosophical problems in physics, biology and psychology.........................................13
Ch7 - Science and its critics......................................................................................................14
Ch1 - what is science
Question: what is meant with the question 'what is science' when philosophers ask it?
Conclusion: what it is that makes something a science
Question: what are important features of science?
Conclusion:
1. The particular methods scientists use to investigate the world
2. The construction of theories
Question: what is one of the key problems in philosophy of science?
Conclusion: to understand how techniques such as experimentation, observation, and theory-
construction have enabled scientists to unravel so many of nature's secrets.
Question: what is philosophy of science?
Conclusion: The principal task of philosophy of science is to analyse the methods of enquiry used
in the various sciences.
Evidence: looking at science from a philosophical perspective allows us to probe deeper - to
uncover assumptions that are implicit in scientific practice, but which scientists do not explicitly
discuss.
Question: what is pseudo-science?
Answer: supposedly scientific theories that do not satisfy the condition of a falsifiable theory
Ch 2 - scientific reasoning
Question: what is the difference between deduction and induction?
Conclusion:
Deduction Induction
All Frenchmen like red wine (premisses Premiss: all x's examined so far have been y'
of the interference) Conclusion: the next x to be examined will he y', or
Pierre is a Frenchman (premisses of the sometimes, `all x's are y
interference)
------------------------------------- Inductive reasoning is quite capable of taking us from
------------------------- true premisses to a false conclusion.
Pierre likes red wine (conclusion)
Despite this defect, we seem to rely on inductive
, What makes the inference deductive is reasoning throughout our lives
the existence of an appropriate
relation between premisses and Scientists use inductive reasoning too (e.g. with DS
conclusion, namely that if the they know you have an extra chromosome)
premisses are true, the conclusion
must be true too The central role of induction in science is sometimes
obscured by the way we talk (proof -> very good
Much safer activity than inductive evidence)
reasoning. When we reason
deductively, we can be certain that if
we start with true premisses, we will
end up with a true conclusion.
Evidence:
Question: is it obvious that science relies heavily on inductive reasoning?
Conclusion: most philosophers think it is, as some things are so obvious no reasoning is
necessary. However, Karl Popper claimed that scientists only need to use deductive inferences.
Although it is not possible to prove that a scientific theory is true from a limited data sample, it is
possible to prove that a theory is false
Question: what is the weakness of Popper's argument?
Conclusion: scientists are not only interested in showing that certain theories are false.
Evidence: When a scientist collects experimental data, her aim might be to show that a particular
theory - her arch-rival's theory perhaps - is false. But much more likely, she is trying to convince
people that her own theory is true. And in order to do that, she will have to resort to inductive
reasoning of some sort
Question: what justifies this faith we place in induction? How should we go about persuading
someone who refuses to reason inductively that they are wrong?
Conclusion: Hume points out that our inductive inferences rest on the UN assumption. But we
cannot prove that UN is true, and we cannot produce empirical evidence for its truth without
begging the question. So our inductive inferences rest on an assumption about the world for
which we have no good grounds. Hume concludes that our confidence in induction is just blind
faith - it admits of no rational justification whatever.
Evidence: we presuppose the 'uniformity of nature' (UN) whenever we make inductive inferences
, Question: what is the uniformity of nature according to Hume?
Conclusion: our reasoning seems to depend on the assumption that objects we haven't examined
will be similar, in the relevant respects, to objects of the same sort that we have examined
Question: what are responses to Hume's problem of induction?
Conclusion: Some people believe the key lies in the concept of probability. Another popular
response is to admit that induction cannot be rationally justified, but to argue that this is not
really so problematic after all.
Question: what is meant with 'inference to the best explanation'?
Conclusion: rationally thinking about plausible events
Evidence: Scientists frequently use IBE
Darwin argued for his theory of evolution by calling attention to various facts about the
living world which are hard to explain if we assume that current species have been
separately created, but which make perfect sense if current species have descended from
common ancestors, as his theory held
Brownian motion refers to the chaotic, zig-zag motion of microscopic particles
suspended in a liquid or gas. After Einstein's work, the kinetic theory was quickly agreed
to provide a far better explanation of Brownian motion than any of the alternatives, and
scepticism about the existence of atoms and molecules rapidly subsided.
Question: is IBE or ordinary induction a more fundamental pattern of inference?
Conclusion: Gilbert Harman: it is more fundamental - whenever we make an ordinary inductive
inference we are implicitly appealing to explanatory considerations. Proponents of this view do
not say there is no difference between IBE and ordinary induction - there clearly is. Rather, they
think that ordinary induction is ultimately dependent on IBE.
Other philosophers: this gets things backwards: IBE is itself parasitic on ordinary
induction. When we try to
decide which of a group of competing hypotheses provides the best explanation of our data, we
invariably appeal to knowledge that has been gained through ordinary induction. Thus it is
incorrect to regard IBE as a more fundamental mode of inference.
Evidence Gilbert Harman: We assume that the correct explanation for why the pieces of metal in
our sample conducted electricity, whatever it is, entails that all pieces of metal will conduct
electricity; that is why we make the inductive inference. But if we believed, for example, that the
explanation for why the pieces of metal in our sample conducted electricity was that a laboratory
technician had tinkered with them, we would not infer that all pieces of metal conduct electricity
Question: how can we decide which of the competing hypotheses provides the best explanation
of the data when using IBE?
Conclusion: popular answer is that the simplest or most parsimonious hypothesis
Evidence: Darwin's theory could explain a very diverse range of facts about the living world, not
just anatomical similarities between species. Each of these facts could be explained in other ways,
as Darwin knew. But the theory of evolution explained all the facts in one go - that is what made
it the best explanation of the data.
Question: is the idea of simplicity or parsimony as the mark of a good explanation widely
accepted?
Conclusion: philosophers of science have not agreed yet
Question: what is known as the frequency interpretation of probability?
Conclusion: it equates probabilities with proportions, or frequencies
Evidence: If you read that the probability of an Englishwoman living to 100 years of age is 1 in 10,
you would understand this as saying that one-tenth of all Englishwomen live to the age of 100.
