Fallacy of Division The fallacy of division is the reverse of
the fallacy of composition. It is committed by inferences from
the fact that a whole has a property to the conclusion that a
part of the whole also has that property. Like the fallacy of
composition, this is only a fallacy for some properties; for
others, it is a legitimate form of inference. An example of an
inference that certainly does commit the fallacy of division is
this: (1) Water is liquid. (2) H2O molecules are liquid. This
argument, in attributing a macro-property of water, liquidity,
to its constituent parts, commits the fallacy of division.
Though water is liquid, individual molecules are not. Note,
however, that an argument with the same logical form but
inferring from the fact that a computer is smaller than a car
that every part of the computer is smaller than a car would not
be fallacious; arguments with this logical form need not be
problematic.