original question: Which quotation subject has the quotations of [The quality of mercy]?
answer: mercy, ethics, justice
answer type: Quotation Subject.
auxiliary information: The quality of mercy is not strain'd,   It droppeth as the gentle rain from heaven   Upon the place beneath. It is twice blest:   It blesseth him that gives and him that takes.
The quotation which is called [The quality of mercy] is referring to what subject?