What Is This Thing Called Science? / Alan Chalmers
Chapter 15:Realism and anti- realism
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Realism = science describes
not just the observable world but also the world that lies behind the
appearances
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Doubts abut realism: extent
to which claims about the unobservable world must be hypothetical to the extent
that they do transcend what can be firmly established on the basis of
observation
Global anti-realism
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We are trapped within
language and cannot break out of it to describe reality directly in a way that
is independent of our theories
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(Realist) correspondence
theory of truth = a sentence is truth if and only if it corresponds to the
facts
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Liar paradox: e.g. I never
tell the truth
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Tarski: avoid paradoxes by
distinguishing the object language (is being talked about) from the meta-language
(in which the talking is done)
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A theory is true if the world is as the theory
says it is and false otherwise
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Should scientific theories
be taken as candidates for truth or as making claims about the observable world
only? Neither side supports global anti-realism
Anti-realism
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Instrumentalists: theories
are just useful instruments to predict results
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Van Fraassen is not an instrumentalist
for theories can be true or false, but the merit is judged in terms of its
generality and simplicity and the extent to which it leads to new observations à constructive
empiricism
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Motivation of anti-realism
= desire to restrict science to those claims that can be justified by
scientific means. Evaluate theories solely in terms of their ability to order
and predict observable phenomena
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Theories can be discarded
when they have outlived their usefulness, and the experimental and
observational discoveries to which they have led retained
Objections and anti-realists response
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Distinction between
knowledge at the observational level (securely established) and is best seen as
an heuristic aid à
problem: theory dependence and fallibility of observation and experiment
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Theories that are
predictively successful have to be more or less true and not just instruments à response
anti-realists: fact that a theory is productive need be no indication that it
is true (historical proof)
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Anti-realists insist that
theories must be general and unified – embrace a wide range of phenomena
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The unobservable has no
place in science or should be treated merely as useful fiction (e.g. atomic
theory) à
response: only part of science that is subject to confirmation by observation
and experiment should be treated as candidates for truth and falsity, but as
science progresses and better instruments and experimental techniques are
devised à
range of claims that can be subject to confirmation is extended
Scientific realism
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Science aims at true
statements about what there is in the world and how it behaves at all levels.
Science has made progress to this aim
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Impossible to know that
current theories are true, but they are truer than earlier theories
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Hacking: pay attention to
what can be practically manipulated in science. Entities in science can be
shown to be real once they can be manipulated in a controlled way and used to
bring about effects in something else
Conjectural realism (Karl Popper)
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Theories of the past have
been falsified and replaced by superior theories
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Problem: weakness of its claims. Science aims
to achieve truth and there are ways to recognize how it falls short of this aim
(there is no truth)
Structural realism
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Middle ground realism and
anti-realism: realist in that it attempt to characterizes the structure of
reality: more and more capable. Representations are replaced over time
Idealization
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Duhem: theories cannot be
taken as literal descriptions of reality because theoretical descriptions are
idealized in a way that the world is not
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Theoretical and
observational knowledge
additional summaries in philosophy of science
Some books about philosophy of science to consider:
