What are examples from Act 1 of "Macbeth" that illustrate the theme of confusion and inversion?(of normally accepted truths)
In Act I, Scene 3, when Macbeth and Banquo meet the three witches in the forest, their minds are challenged to believe what they see with their eyes. Also, they are hard pressed to believe the prophecy that is told to them by the witches. Macbeth receives the news with great disbelief and confusion. And they can barely believe their eyes when the witches disappear.
Into the air; and what seem'd corporal melted
As breath into the wind. Would they had stay'd!
Were such things here as we do speak about?
Or have we eaten on the insane root
That takes the reason prisoner? (I.iii)
The supernatural was very significant in the time in which Macbeth was written 1606/1607. Belief in witches and black magic was a strong force in the society of Scotland in King James I's time. Therefore it was natural for Macbeth and Banquo to question what they see and hear from the mysterious weird sisters, the witches.
The theme of confusion starts in scene 1, when the witches are chanting. For example, saying they'd meet when the battle is both lost and won is an inversion of the normal state of things. Usually it is either won or lost, but in this case, it will be both.
This continues in the second scene, when the soldier is reporting from the battle. He reports that when Macbeth won a victory, it seemed to lead to evil, rather than to good (an inversion), but that Macbeth and the others stayed strong, rather than being dismayed (another inversion of the normal state of affairs). Finally, look at the last line in scene 2; one man's loss is Macbeth's gain—but in gaining from a traitor, Macbeth starts down the road to treason himself.
In terms of inversion, I think the most interesting and often overlooked example involves the use of trochaic and iambic pentameter. The witches appear using trochaic meter to communicate their message: "Fair is foul and foul is fair." When Macbeth appears, he says, "So fair and foul a day...". Not only is this inversion - trochaic meter is an inversion of iambic meter - it also communicates a connection between Macbeth and the witches.
Another inversion is simply Lady Macbeth telling Macbeth what to do. This is the complete opposite of what should happen in traditional Renaissance philosophy. Men were masters over women - not the inversion as Lady Macbeth has demonstrated.