In Act V of The Tragedy of Macbeth by William Shakespeare, why does Macbeth believe that Malcolm cannot harm him?
Because Malcolm was "born of a woman" -- that is, naturally.
The witches explain to Macbeth that he will not be killed by anyone born of a woman. Macbeth interprets this to mean that he cannot be killed by anyone , since everyone is born of woman. This is the reason why he is not intimidated by Malcolm; because he's sure that Malcolm falls under those guidelines.