How does Shakespeare develop the them of "fate versus free will" in act 4, scene 1, of Macbeth? How has the theme evolved since the beginning of the...

There is an
interesting tension within between free will and fate: on the one
hand,does clearly assert agency (after all, he actively engineers his rise to power and the same
can be said of his eventual downfall), but at the same time, you might get a sense, reading this
play, that the power of fate is something too great for any one person to truly resist or
overcome.

This is perhaps most clearly illustrated in the example of , whose
children are prophesied to become kings. If we look toward Shakespeare's own time, Banquo was
believed to be an ancestor to the Stuarts (including Shakespeare's own patron, King James I of
England and Scotland). This particular prophesy, then, would ultimately be fulfilled across a
span of centuries.

Thus, there is a great deal of complication as to where
free will begins and where it ends, because Macbeth is simultaneously culpable for his own
crimes (an agent of his own ambition), but he is also subject to the manipulations and demands
of fate (and even perhaps a pawn to them). The events of act 4, scene 1, maintain this tension;
when the subject of prophesy returns, the repercussions of which will loom over the rest of the
play.

In this scene, Macbeth again meets withand receives new prophesies
(which he will misinterpret, to his eventual doom). Three apparitions are conjured. The first
warns him of , the second famously states:

Be bloody, bold
and resolute: laugh to scorn
The power of man, for none of woman born
Shall
harm Macbeth (4.1.79€“81)

The next reads:

Macbeth shall never vanquish'd be until
Great Birnam wood
to high Dunsinane hill
Shall come against him. (4.1.92€“94)

These prophesies describe Macbeth's eventual destruction at the
hands ofand Macduff. As we find out later in the play, Birnam Wood will (in a sense) go on the
march, and (later still) we'll learn that Macduff had been born from a C-section.

Thus, these prophesies are directly alluding to Macbeth's eventual downfall, but
Macbeth himself misunderstands the meaning of the prophesies as relating to his own
invulnerability. Thus, in his arrogance, he will proceed to underestimate the threat Malcolm and
Macduff representa factor which does play a role in his eventual defeat.

In
this respect, we again see the intertwining of free will and fate because, ultimately, while
these prophesies are fulfilled to a certain degree, it's worth wondering how much they actually
depend upon Macbeth's misinterpreting them to take effect (which brings us back to the subject
of agency vis-a-vis Macbeth).