" words differentiate in suitably contrasting environments.
  Satisfactory explanation for that must, logically, precede an
  account of derivative meanings." ok : basically, how can the
  same words have multiple meaning? Context is a word we throw
  around without really 'getting it'. But consider: "this derives
  from this other thing". We take that as pretty basic in much of
  our ways of thinking. But does it REALLY derive or does the
  meaning "grow" differently depending on the environment it finds
  itself in? How can the same sentence have different meanings
  depending on the surrounding sentences? It does, it can. Just a
  little thought can easily bring examples of the same sentence
  meaning different things. Context. Consider the significance of
  this. We may never find the 'root' and we might. But whether or
  not we do, once the process started, HOWEVER it started, the
  context creates the environment that allows the meaning of words
  to shift and change. "Make" has so many meanings not because
  there is ONE DEFINITIVE meaning of "make" that all else derived
  from. Maybe the first sentence. But not the second and beyond.
  Meanings grow. This fact is obscured when the absolute precision
  of word to definition is required in certain disciplines. One
  can be led to believe that meaning is constructed of meaning.
  But really, it's not constructed of meaning. It's grown within
  environments. It's the inertial resistance to change that keeps
  word meanings "generally" similar but still, words grow and
  change just the same. No constraints seem to be absolute.