These considerations
make it obvious why arithmetic
and geometry
prove to be much more certain
than other disciplines: they alone are
concerned with an
object so pure and simple
that they make no
assumptions that experience might render uncertain; they consist
entirely
in deducing conclusions by
means of rational arguments. They
are
therefore the easiest and clearest of all the sciences and have just
the sort
of object we are looking
for. Where these sciences are
concerned it
scarcely seems humanly possible to err, except through
inadvertence. Yet
we should not be surprised if many prefer
of their own accord to apply
their minds to other arts, or to
philosophy. The reason for this is that
everyone feels free to make more confident
guesses about matters which
are obscure than about matters
which are clear. It is much
easier to
hazard some conjecture on this or
that question than to arrive at the
exact truth about one particular
question, however straightforward it
may be.
Rene Descartes, "Rules for the Direction of the Mind"
(orig. lat. ''Regulae ad directionem ingenii", 1619)