What is the meaning of "fair is foul and foul is fair"? Act I scene 1I dunno if this is different from the first question but oh well. How...

The three witches speak this line together at the close of
the opening scene of Macbeth. The line sounds paradoxical because
of the syntactic inversion called chiasmus in the line. The two
words fair & foul appear and re-appear
in this line and the deliberate repetition shows an inversion. The line spoken by the
witches in chorus reads like an ambiguous formula thrown into the desert air by the
weird sisters so as to strike the key-note of the whole play in which Macbeth, whom the
witches want to meet, is going to be an embodiment of both fair
& foul. The line with its queer syntactic
inversion tends to suggest a deeper moral inversion: Macbeth who is so fair because of
his exemplary courage and skill is also so foul because of his evil ambition to usurp
the throne by killing king Duncan.