Do the images of witches contribute to the evil atmosphere in Macbeth?

The Witches or the Weird Sisters certainly contribute to the evil atmosphere in the play. But not in its entirety.

The Elizabethans always believed in the existence of the Witches and therefore, when Shakeseare wrote the play, he was only keeping in mind the requirements of his audience, like any other playwright.

However, when we come to think of it in a different perpective, the actions that the witches caused were indeed, quite evil. The prohpecies made by the Witches accelerated an already scheming-mind in Macbeth, and led him to do what ultimately kills him in the end. Moreover, we must also understand that you cannot make a person do something, if he hasnt already been thinking about doing it sub-consciously. Macbeth obviously had very big dreams, that of being the King of Scotland one day, which is why when he heard the Witches prophecies, he saw an outlet from which his dreams could actually come true. This, along with the deep influence of his unscrupolous wife, led him to the timely murders, ths earning him the name of a 'tyrant' and a 'dwarfish theif' who is unable to fit into a 'giat's robe' by his once-adoring and admiring public.

There are several other factors that contribute to the evil facets in the play. The atmosphere itself, was quite dark, gloomy and mysterious. The daylight did not bring any new hope, and continued to contribute to the gloomy theme of the play. The unnatural incidents that occur, may also be considered reponsible.