When you hammer copper it hardens...
...Just as we humans aren't all the same, and in the face of
difficulty we behave in
different ways, so some materials, like felt and leather, improve if you hammer
them, and so does iron, which, if you hammer it, spits out the dross and
becomes stronger...
...You have to be careful with similes, because they may
be poetic, but they don't prove much, so you have to watch your step when
drawing educational or edifying lessons from them.
Should the educator take as his model the smith, who roughly pounds the
iron and gives it shape and nobility, or the vintner, who achieves the
same result with wine, separating himself from it and shutting it in the
darkness of a cellar? Is it better for the mother to imitate the pelican,
who plucks out her feathers, stripping herself, to make the nest for her
little ones soft, or the bear, who urges her cubs to climb to the top of
the fir tree and then abandons them there, going off without a backward
glance? Is quenching a better didactic system than the tempering that
follows it?
Beware of analogies: for millennia they corrupted medicine, and it may
be their fault that today's pedagogical systems are so numerous, and that
after three thousand years of argument we still don't actually know which
is best.
- Primo
Levi, The Wrench