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arguments. The banana-flavored
cat argument, as we have seen,
is valid but not sound—whereas
the argument about apples and
fruit is both valid and sound.
Falsifiability
Deductive arguments could be said
to be like computer programs—the
conclusions they reach are only as
good as the data that is fed into
them. Deductive reasoning has
an important role to play in the
sciences, but on its own, it cannot
say anything about the world. It
can only say “If this is the case,
then that is the case.” And if we
want to use such arguments in the
THE MODERN WORLD
Science may be described
as the art of systematic
over-simplification.
Karl PopperExperiments can show that certain
phenomena reliably follow others in
nature. But Popper claims that no
experiment can ever verify a theory,
or even show that it is probable.Karl Popper at the University of London.
He was knighted in 1965, and
remained in England for the rest
of his life. Although he retired in
1969, he continued to write and
publish until his death in 1994.Key works1934 The Logic of Scientific
Discovery
1945 The Open Society and Its
Enemies
1957 The Poverty of Historicism
1963 Conjectures and
Refutations: The Growth of
Scientific KnowledgeKarl Popper was born in Vienna,
Austria, in 1902. He studied
philosophy at the University of
Vienna, after which he spent six
years as a schoolteacher. It was
during this time that he published
The Logic of Scientific Discovery,
which established him as one
of the foremost philosophers of
science. In 1937, he emigrated
to New Zealand, where he lived
until the end of World War II,
and where he wrote his study of
totalitarianism, The Open Society
and Its Enemies. In 1946, he moved
to England to teach, first at the
London School of Economics, thensciences, we still have to rely on
induction for our premises, and
so science is lumbered with the
problem of induction.
For this reason, according to
Popper, we cannot prove our
theories to be true. Moreover, what
makes a theory scientific is not that
it can be proved at all, but that it
can be tested against reality and
shown to be potentially false. In
other words, a falsifiable theory
is not a theory that is false, but
one that can only be shown to be
false by observation.
Theories that are untestable (for
example, that we each have an
invisible spirit guide, or that God
created the universe) are not part
of the natural sciences. This does
not mean that they are worthless,
only that they are not the kinds of
theories that the sciences deal with.
The idea of falsifiability does not
mean we are unjustified in having
a belief in theories that cannot be
falsified. Beliefs that stand up to
repeated testing, and that resist
our attempts at falsification, can be
taken to be reliable. But even the
best theories are always open to
the possibility that a new result
will show them to be false.Popper’s work has not been without
its critics. Some scientists claim
that he presents an idealized view
of how they go about their work,
and that science is practiced very
differently from how Popper
suggests. Nevertheless, his
idea of falsifiability is still used in
distinguishing between scientific
and non-scientific claims, and
Popper remains perhaps the most
important philosopher of science
of the 20th century. ■