I feel that Shakespeare would completely agree with Lord Acton's words, especially in the context of Macbeth. Although most of the plot is based around the theme of the supernatural, there is much to be said about power and the role corruption plays in how it is gained and used in Macbeth. Macbeth's initial power is gained through his own choices when he becomes the Thane of Cawdor by defeating the man who previously held that title when he was revealed as a traitor. But after he hears the prophecy given by the weird sisters and hears of the power that he will have he is changed. In having been given even a little power Macbeth is influenced to kill King Duncan, this is the first evidence of corruption. He is influenced by Lady Macbeth who is the one being corrupt when she hears of the power she can gain through her husband (herein lies another argument about whether women are more easily corrupted than men).
Once Macbeth has murdered Duncan there is no turning back for him. As the King Macbeth has absolute power and it is evident that he is willing to do anything to keep it. This is the exact type of absolute corruption that Lord Acton speaks of. Macbeth goes so far as to kill his best friend and uses his power to rationalize doing so. Before talking to the murderers he will convince to execute his plan, Macbeth says to himself "Upon my head they placed a fruitless crown/And put a barren scepter in my grip/.../For Banquo’s issue have I filed my mind/For them the gracious Duncan have I murdered/ Put rancors in the vessel of my peace/ Only for them; and mine eternal jewel/ Given to the common enemy of man,/ To make them kings, the seed of Banquo kings!/ Rather than so, come fate into the list/ And champion me to th' utterance." Because Macbeth knows that he will not keep his power and pass it on to a child he fears that everything that he has done has been for Banquo and his children. He knows that fate is playing a role and that it is Banquo's sons destiny to become Kings just as it was his he is willing to challenge it to keep his power for himself even if that means killing Banquo and Fleance.
