If appropriate and inappropriate remarks and passable and impassable
mountain trails are opposites, why are
flammable and inflammable materials, heritable and inheritable
property, and passive and impassive people
the same and valuable objects less treasured than invaluable ones? If
uplift is the same as lift up, why are
upset and set up opposite in meaning? Why are pertinent and
impertinent, canny and uncanny, and famous
and infamous neither opposites nor the same? How can raise and raze
and reckless and wreckless be
opposites when each pair contains the same sound?
-- Richard Lederer. Crazy English: the Ultimate Joy Ride Through
Our Language (http://pw1.netcom.com/~rlederer/index.htm)