To what extent was Macbeth responsible for his own downfall?

To answer this question successfully you will need to define what we might mean by the word 'responsible'. What is the most appropriate definition for the word 'responsible' as it applies to the play? Do we need a legal, ethical, philosophical or moral definition? Do we need to take into account the idea of free will and/or determinism when we try to assess a person's responsibility? Under what circumstances can it be argued that someone is or is not responsible for their own action