If you were looking for evidence to support a theme that had something to do with responsibility

Responsibility is a sign of having good character. Someone who is Irresponsible like "Johnny Test" often break the rules, causing injury to themselves and others. They can't be trusted for doing important deeds. Basing my knowledge in what I know about Julius Caesar's tragedy just to put an example. It has much evidence which has to do with responsibility. Take the side of Brutus for example: 

Here is a chat between Cassius and Brutus. Cassius wants Brutus to join his secret group of jealous senators to murder Caesar. 

pg. 17 using the version (Classic for young reader or SV) of the play

Brutus: I do fear the people choose Caesar as their king. 
Cassius: Do you fear it? Then must I think you would not have it so
Brutus: I would not Cassius yet I love him well... If it ought for the general good, I love the name of honor more than I fear death 

The summary of this conversation is that Brutus or known as to be Caesars best friend and "an honorable nobleman" is being persuaded by Cassius to stop Caesars coronation as being king or Emperor of Rome. If you look at Caesars both strong and weak side you can see that he was a great soldier and valient leader that ruled Rome with justice. However, he is compared as a Hitler in the article or webpage:http://hubpages.com/education/Julius-Caesar-Hero-or-Hitler there is stated: "Goldsworthy opines that while Caesar was kind, generous "inclined to forget grudges and turn enemies into friends " he was nonetheless "utterly ruthless ".
 Proving that he had both a good side and a bad one. Where is this all leading too? Well having taken all this in consideration Brutus had the right to plot the murder of Caesar since his intentions were honorable. It was Brutus responsibility to free Rome of Caesars hands (see pages. 16 and 54)

Julius Caesar is not the only book which has the presence of need of responsibility books such as Among the Hidden, etc. show how protagonist show responsibility to save themselves and others from peril or anything else. 

Something that was made by us humans rather than being found in nature