Although Macbeth was responsible for his own decision making, could it be argued that his ultimate demise was not completely his fault?
There is certainly evidence to support the idea that Macbeth’s judgment was heavily influenced, if not taken over, by others.
When Macbeth and Banquo first meet the witches in Act 1 scene iii, he is warned by Banquo that they often mislead the innocent by tapping into their unconscious desires-
And oftentimes, to win us to our harm,
The instruments of darkness tell us truths,
Win us with honest trifles, to betray's
In deepest consequence—
The witches at least stir up ideas within Macbeth which lead to his killing of the king.
The forces of evil are strong, but so are the forces of love. Lady Macbeth similarly draws her husband in to the bloody crime by persuading him that it is a promise to her that he should keep if he has honour as a man--
What beast was't then
That made you break this enterprise to me?
When you durst do it, then you were a man;
And, to be more than what you were, you would
Be so much more the man. Nor time nor place
Did then adhere, and yet you would make both:
They have made themselves, and that their fitness now
Does unmake you. I have given suck, and know
How tender ’tis to love the babe that milks me:
I would, while it was smiling in my face,
Have pluck'd my nipple from his boneless gums,
And dash'd the brains out, had I so sworn as you
Have done to this.
Her words are strong, harsh and play heavily upon his reputation and the close bond with his wife. He is therefore driven as much by these feminine wiles and supernatural solicitings as he is by his own free will.