Thriftless ambition, that wilt ravin up
Thine own life’s means!
– William Shakespeare
Macbeth, Act 2, Scene 4. Ross comments on the wasteful ambition that would cause sons to kill the father who gave them life. He is talking about Duncan’s sons’ supposed involvement in their father’s murder. He is right about ambition being the cause of Duncan’s murder, but it was Macbeth’s ambition and not that of Malcolm and Donalbain.