Through watching Macbeth you can definitely tell his mind have a strong hold on what actions are taken. At the beiginning of the story he has juts gone through a hard war, ending for victory on his side. I believe this gave Macbeth a lasting sense of importance and feeling of huge power- that he was able to do anything. Especially since the king granted him an award for it all. Throughout the story his person continues to grow wrapped up in a power rage, only killing more and more people and gaining "power".
His wife also plays an important part in this, urging him on do to whatever he has to do. But as this is all done they all slowly lose their minds, wracked with the guilt of murder and a heavy concsious.