quotes
"is this dagger which I see before me,/ The handle towards my hand?"
He sees a vision leading him to Duncan's murder showing that his mind is pushing him towards it. This can be interpreted as fate guiding him or his mind pushing him towards a choice he feels destined to make.
“If it were done when ’tis done, then ’twere well / It were done quickly”
shows the internal conflict he has. Macbeth knows he has a choice whether to kill Duncan or not and that fate is not forcing him to do so.
“None of woman born / Shall harm Macbeth.”
This prophecy makes Macbeth feel invincible, as he believes that all humans are born from women, so this must mean that no person can kill him. It shows how fate can be misleading and give false confidence.
“If chance will have me king, why, chance may crown me, / Without my stir”
This shows that Macbeth is aware he has a choice, while considering letting fate take control rather than acting violently
"I am in blood / Stepped in so far that, should I wade no more, / Returning were as tedious as go o'er."
This demonstrates that Macbeth is carefully choosing to live with the consequences of his first choice by creating more blood, showing he is making a conscious choice to continue, even though he recognises the consequences.
“My thought, whose murder yet is but fantastical”,
showing that although fate may predict, choice begins in his mind, having his own thoughts form events