Northrop Frye said this quote

Literature keeps presenting the most vicious things to us an entertainment, but what it appeals to is not any pleasure of these things, but the exhilaration of standing apart from them and being able to see them for what they are because they aren't really happening. The more exposed we are to this, the less likely we are to find an unthinking pleasure in cruel or evil things. As the eighteenth century said in a fine mouth-filling phrase, literature refines our sensibilities.