The long-running feud between the Montagues and Capulets is a prominent factor that brings forth the idea that human responsibility did indeed lead to the deaths of the young couple. As a result of the families" unreasonable anger and the inexhaustible hatred that was so powerfully directed towards their enemy, Romeo and Juliet's relationship was no more than a conspiracy, where they were forced to hide the true nature and the intensity of their bond. The origin of the quarrel and the cause of such hatred was not even known- thus the term "ancient grudge", yet the two families" thoughtless actions managed to lead to the tragic losses of their beloved, something that could have been avoided so easily .
A significant role that displayed irresponsible behaviour was that of Friar Lawrence. The Franciscan's outrageous creatings led to the plan for Juliet's fake death, as he believed that he would be the saviour .
of fair Verona and end the tedious battle between the two families once and for all. Although he is described as wise and humane, he was not being realistic when producing his "clever" ideas and his eagerness to help, ruled out any possible chances of his thinking out the consequences to such reckless actions and therefore basing his ideas on hope and the glory of reconciling the families. "Take thou this vial, being then in bed, And this distilling liquor drink thou off .", are the words spoken by the Friar to Juliet after learning of Romeo's punishment. He gives no thought as to the consequences or perhaps any problems that they may be faced with along the way. To a great extent, the influences he had on the young couple and the decisions he placed on their heads led to their deaths, and this very powerfully highlighted that human responsibility was the cause of their misfortunate deaths.
Two other notable characters that raised the idea that human responsibility was the reason for the unnecessary deaths were Tybalt; nephew of Lady Capulet, and Mercutio; friend of Romeo.