In a different vein than what people are sure to say about religion, and the probable ties to the Protestant Reformation, and the changes in art and views of mortality, which you can find in [Danse Macabre depictions] (http://en.wikipedia.org/wiki/Danse_Macabre), thanks to the plague came an increased focus on individuality and the value of one's labor. With a severely decimated population came a decimated work force. Laborers who had been tied to land were able to leave manors and demand higher wages as labor was in high demand. These individuals began to realize that the power had shifted and through their potential labor they had gained leverage against employers. Laborers were able to choose what land they worked and for how much, and if the terms were not agreeable they would simply go elsewhere. This is a departure from the manorial system where people were forced to inherit land and work for lords. Where land had once been scarce and overworked, people were now able to have their own land to work, as well as the choice of working the land of the upper class who desperately needed laborers.

Sources:

The Black Death: A Personal History by John Hatcher

The Black Death by Rosemary Horrox

The Black Death: Natural and Human Disaster in Medieval Europe by Robert Gottfried

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