Explain why Donne questions the fidelity of women in his poem "Go and catch a falling star."

It is important to note how John Donne is actually being
quite counter-cultural in this poem. In contrast with other Renaissance songs that
idealise women, this song satirises them using hyperbole to underline the point. We
can't be completely sure what prompted this rather cynical poem which argues that a true
and beautiful woman could not be found, but perhaps we could infer that the speaker is
writing after the end of an unhappy romance which might have occasioned the bitterness
expressed in this poem.

Bitter it certainly is, for, the
speaker assures his hearer, even if a "true" woman could be found, the speaker will
still not bother coming to see her because in the time it would take him to arrive she
would be unfaithful:

readability="16">

Though she were true, when you met
her,

And last, till you write your
letter,

Yet she

Will
be

False, ere I come, to two, or
three.

The cynicism and
sardonic bitterness in these last lines that suggest that a "true" woman would betray
two or three men in the time it would take to visit her strongly suggests that this is a
poem written after the end of a bad relationship that makes the speaker believe  that
"Nowhere/Lives a woman true, and fair."