Discuss the features of metaphysical poetry in "A Valediction: Forbidding Mourning."

One feature in "A Valediction:  Forbidding Mourning" that
reflects what we, today, label metaphysical poetry is stretched metaphors or conceits. 
Four of the stretched metaphors, with explanations,
follow:

1. Separation of death compared with
   separation when one lover leaves another (stanzas one & two).  Let we two lovers
   not cry or sigh, but keep our separation to ourselves.  The idea is that to speak
   loosely about their feelings is to lose them.


2. Movement of
   the earth draws attention to itself, yet movement among the stars, which is movement of
   far more importance, goes unnoticed (stanzas three-five).  Their love is like the
   movement of the stars.  It doesn't need to draw attention to itself to be monumental. 
   They don't need to cry or make a show of their
   separation.


3. Their love does not suffer a breach, or
   break, but experiences an expansion:  like gold that is beaten to airy thinness (stanza
   six).


4. Their love is like two legs of a compass.  One leg
   travels around, but is always connected to and anchored by the other.  Two legs of a
   compass cannot be fully separated, just as the two lovers can never really be
   separated. 

The most famous of the conceits is
the final one.  The metaphor is stretched in the sense that two things not usually
thought to have any thing in common are compared--the legs of a compass are compared to
two lovers.  The metaphor is highly artificial and witty, artsy, if you will.  This is
one of the marks of metaphysical poetry.