In the play Julius Caesar the tool of nature vs. the actions of humans was prevalent. Nature reflected the anger of the gods at the humans and the events that transpired. This is present as the conspirators meet and plot the sky "throws fire" and many very strange fates combine to paint a picture that the actions of the people in the play are unwanted. Of course, the conspirators see these circumstances as the reason they must end Caesar; he is the reason for the weird happenings. Shakespeare adds the natural mysteries in to add to the confusion and heighten the imminent destruction of Rome.
This relationship was a belief of the Romans and Shakespeare also. Shakespeare used it to show that nature cannot possibly be in check if man is not first. This tool is not only a dramatic and cultural belief, but a religious one as well; the environment reflects the way the world is. According to the Bible, the sky turned dark when Jesus died and the rain came down when God was displeased with the human race. The tigers were loose from the circus when Caesar's conspirators were plotting against him and the storm raged on as they agreed to kill him in senate on the ides of March.